\documentclass[journal=jctcce,manuscript=article,layout=traditional]{achemso} \usepackage{graphicx,dcolumn,bm,xcolor,microtype,hyperref,multirow,amsmath,amssymb,amsfonts,physics,float,lscape,soul,rotating,longtable} \usepackage[version=4]{mhchem} \newcommand{\alert}[1]{\textcolor{red}{#1}} \newcommand{\mc}{\multicolumn} \newcommand{\mcc}[1]{\multicolumn{1}{c}{#1}} \newcommand{\mr}{\multirow} \newcommand{\EFCI}{E_\text{FCI}} \newcommand{\EexCI}{E_\text{exCI}} \newcommand{\EsCI}{E_\text{sCI}} \newcommand{\EPT}{E_\text{PT2}} \newcommand{\PsisCI}{\Psi_\text{sCI}} \newcommand{\Ndet}{N_\text{det}} \newcommand{\ex}[6]{$^{#1}#2_{#3}^{#4}(#5 \rightarrow #6)$} \newcommand{\pis}{\pi^\star} \newcommand{\si}{\sigma} \newcommand{\sis}{\sigma^\star} % methods \newcommand{\TDDFT}{TD-DFT} \newcommand{\CASSCF}{CASSCF} \newcommand{\CASPT}{CASPT2} \newcommand{\ADC}[1]{ADC(#1)} \newcommand{\AD}{ADC(2)} \newcommand{\CCD}{CC2} \newcommand{\CCT}{CC3} \newcommand{\STEOM}{STEOM-CCSD} \newcommand{\AT}{ADC(3)} \newcommand{\CC}[1]{CC#1} \newcommand{\CCSD}{CCSD} \newcommand{\EOMCCSD}{EOM-CCSD} \newcommand{\CCSDT}{CCSDT} \newcommand{\CCSDTQ}{CCSDTQ} \newcommand{\CI}{CI} \newcommand{\sCI}{sCI} \newcommand{\exCI}{exFCI} \newcommand{\FCI}{FCI} % basis \newcommand{\Pop}{6-31+G(d)} \newcommand{\AVDZ}{\emph{aug}-cc-pVDZ} \newcommand{\AVTZ}{\emph{aug}-cc-pVTZ} \newcommand{\DAVTZ}{d-\emph{aug}-cc-pVTZ} \newcommand{\AVQZ}{\emph{aug}-cc-pVQZ} \newcommand{\DAVQZ}{d-\emph{aug}-cc-pVQZ} \newcommand{\TAVQZ}{t-\emph{aug}-cc-pVQZ} \newcommand{\AVFZ}{\emph{aug}-cc-pV5Z} \newcommand{\DAVFZ}{d-\emph{aug}-cc-pV5Z} % units \newcommand{\IneV}[1]{#1 eV} \newcommand{\InAU}[1]{#1 a.u.} \newcommand{\Ryd}{\mathrm{R}} \newcommand{\Val}{\mathrm{V}} \newcommand{\Fl}{\mathrm{F}} \newcommand{\ra}{\rightarrow} \newcommand{\SI}{Supporting Information} \setcounter{table}{0} \setcounter{figure}{0} \setcounter{page}{1} \setcounter{equation}{0} \renewcommand{\thepage}{S\arabic{page}} \renewcommand{\thefigure}{S\arabic{figure}} \renewcommand{\theequation}{S\arabic{equation}} \renewcommand{\thetable}{S\arabic{table}} \renewcommand{\thesection}{S\arabic{section}} \renewcommand\floatpagefraction{.99} \renewcommand\topfraction{.99} \renewcommand\bottomfraction{.99} \renewcommand\textfraction{.01} % addresses \newcommand{\LCPQ}{Laboratoire de Chimie et Physique Quantiques, Universit\'e de Toulouse, CNRS, UPS, France} \newcommand{\CEISAM}{Laboratoire CEISAM - UMR CNRS 6230, Universit\'e de Nantes, 2 Rue de la Houssini\`ere, BP 92208, 44322 Nantes Cedex 3, France} \newcommand{\Pisa}{Dipartimento di Chimica e Chimica Industriale, University of Pisa, Via Moruzzi 3, 56124 Pisa, Italy} \title{Highly-Accurate Reference Excitation Energies and Benchmarks: Medium Size Molecules\\Supporting Information} \author{Pierre-Fran{\c c}ois Loos} \email{loos@irsamc.ups-tlse.fr} \affiliation[LCPQ, Toulouse]{\LCPQ} \author{Filippo Lipparini} \affiliation[DC, Pisa]{\Pisa} \email{filippo.lipparini@unipi.it} \author{Martial Boggio-Pasqua} \affiliation[LCPQ, Toulouse]{\LCPQ} \author{Anthony Scemama} \affiliation[LCPQ, Toulouse]{\LCPQ} \author{Denis Jacquemin} \email{Denis.Jacquemin@univ-nantes.fr} \affiliation[UN, Nantes]{\CEISAM} \begin{document} \clearpage \section{Basis set and frozen-core effects} \subsection{Cyanoacetylene, cyanogen, and diacetylene} \begin{table}[htp] \caption{\small CC3 vertical transition energies of cyanoacetylene, cyanogen, and diacetylene using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S1} \begin{small} \begin{tabular}{l|cccccccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & \multicolumn{2}{c}{\AVQZ} & \multicolumn{2}{c}{\DAVQZ} & {\AVFZ} \\ & FC & FC &FC & FC & Full & FC & Full & FC \\ \hline & \multicolumn{8}{c}{Cyanoacetylene} \\ \hline $^1\Sigma^-$ &6.02 &5.92 &5.80 &5.79 &5.79 &5.79 &5.79 &5.79 \\ $^1\Delta$ &6.29 &6.17 &6.08 &6.06 &6.07 &6.06 &6.07 &6.06 \\ $^3\Sigma^+$ &4.44 &4.43 &4.45 &4.46 &4.46 &4.46 &4.46 &4.47 \\ $^3\Delta$ &5.35 &5.28 &5.22 &5.22 &5.21 &5.22 &5.21 &5.22 \\ $^1A''$[F] &3.70 &3.60 &3.54 &3.54 &3.54 & & & \\ \hline & \multicolumn{8}{c}{Cyanogen} \\ \hline $^1\Sigma_u^-$ &6.62 &6.52 &6.39 &6.38 &6.38 &6.38 &6.38 &6.38 \\ $^1\Delta_u$ &6.88 &6.77 &6.66 &6.64 &6.65 &6.64 &6.65 &6.64 \\ $^3\Sigma_u^+$ &4.92 &4.89 &4.90 &4.91 &4.91 &4.91 &4.91 &4.92 \\ $^1\Sigma_u^-$[F] &5.27 &5.19 &5.06 &5.05 &5.05 &5.05 &5.05 &5.04 \\ \hline & \multicolumn{8}{c}{Diacetylene} \\ \hline $^1\Sigma_u^-$ &5.57 &5.44 &5.34 &5.33 &5.34 &5.33 &5.34 &5.33 \\ $^1\Delta_u$ &5.83 &5.69 &5.61 &5.60 &5.60 &5.60 &5.60 &5.60 \\ $^3\Sigma_u^+$ &4.07 &4.06 &4.08 &4.10 &4.09 &4.10 &4.09 &4.11 \\ $^3\Delta_u$ &4.93 &4.86 &4.80 &4.80 &4.80 &4.80 &4.80 &4.80 \\ \hline \end{tabular} \end{small} \end{table} \clearpage \subsection{Cyclopropenone, cyclopropenethione, and methylenecyclopropene} \begin{table}[htp] \caption{\small CC3 vertical transition energies of cyclopropenone, cyclopropenethione, and methylenecyclopropene using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S2} \begin{small} \begin{tabular}{l|ccccccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & \multicolumn{2}{c}{\AVQZ} &{\DAVQZ} & {\AVFZ} \ \\ & FC & FC &FC & FC & Full & FC & FC \\ \hline & \multicolumn{7}{c}{Cyclopropenone} \\ \hline $^1B_1 (n \rightarrow \pi^\star)$ &4.32 &4.22 &4.21 &4.23 &4.22& 4.23 & 4.23\\ $^1A_2 (n \rightarrow \pi^\star)$ &5.68 &5.59 &5.57 &5.58 &5.57& 5.58 & 5.58\\ $^1B_2 (n \rightarrow 3s)$ &6.39 &6.21 &6.32 &6.37 &6.38& 6.36 & 6.38\\% $^1B_2 (\pi \rightarrow \pi^\star)$ &6.70 &6.56 &6.54 &6.56 &6.56& 6.56 & 6.56\\ $^1B_2 (n \rightarrow 3p)$ &6.92 &6.88 &6.96 &6.99 &7.00& 6.96 & 6.99\\ $^1A_1 (n \rightarrow 3p)$ &7.00 &6.88 &7.00 &7.05 &7.06& 7.03 & 7.06\\ $^1A_1 (\pi \rightarrow \pi^\star)$ &8.51 &8.32 &8.28 &8.28 &8.28& 8.22 & 8.26\\ $^3B_1 (n \rightarrow \pi^\star)$ &4.02 &3.90 &3.91 &3.93 &3.92& 3.93 & 3.94\\ $^3B_2 (\pi \rightarrow \pi^\star)$ &4.92 &4.90 &4.89 &4.91 &4.90& 4.91 & 4.92\\ $^3A_2 (n \rightarrow \pi^\star)$ &5.48 &5.38 &5.37 &5.39 &5.37& 5.39 & 5.39\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &6.89 &6.79 &6.83 &6.84 &6.83& 6.84 & 6.85\\ \hline & \multicolumn{7}{c}{Cyclopropenethione} \\ \hline $^1A_2 (n \rightarrow \pi^\star)$ &3.46 &3.47 &3.43 &3.44 &3.42& 3.44 & 3.43 \\ $^1B_1 (n \rightarrow \pi^\star)$ &3.45 &3.42 &3.43 &3.45 &3.43& 3.45 & 3.46\\ $^1B_2 (\pi \rightarrow \pi^\star)$ &4.67 &4.66 &4.64 &4.66 &4.64& 4.66 & 4.66 \\ $^1B_2 (n \rightarrow 3s)$ &5.26 &5.23 &5.34 &5.39 &5.39& 5.38 & 5.40 \\ $^1A_1 (\pi \rightarrow \pi^\star)$ &5.53 &5.52 &5.49 &5.49 &5.48& 5.49 & 5.49\\ $^1B_2 (n \rightarrow 3p)$ &5.83 &5.86 &5.93 &5.95 &5.95& 5.91 & 5.95 \\%$^a$, mais les autres aussi !! $^3A_2 (n \rightarrow \pi^\star)$ &3.33 &3.34 &3.31 &3.31 &3.29& 3.31 & 3.31 \\ $^3B_1 (n \rightarrow \pi^\star)$ &3.34 &3.30 &3.31 &3.34 &3.32& 3.34 & 3.35\\ $^3B_2 (\pi \rightarrow \pi^\star)$ &4.01 &4.03 &4.02 &4.04 &4.03& 4.04 & 4.05 \\ $^3A_1 (\pi \rightarrow \pi^\star)$ &4.06 &4.09 &4.03 &4.04 &4.02& 4.04& 4.03 \\ \hline & \multicolumn{7}{c}{Methylenecyclopropene} \\ \hline $^1B_2 (\pi \rightarrow \pi^\star)$ &4.38 &4.32 &4.31 &4.31 &4.31& 4.31& 4.32 \\% 5Z: 4.32 $^1B_1 (\pi \rightarrow 3s)$ &5.65 &5.35 &5.44 &5.47 &5.48& 5.46& 5.47\\% 5Z: 5.47 $^1A_2 (\pi \rightarrow 3p)$ &5.97 &5.86 &5.95 &5.98 &5.99& 5.96& \hl{xxx}\\ %N122 $^1A_1 (\pi \rightarrow \pi^\star)$ &6.17 &6.15 &6.13 &6.09 &6.10& 5.98& 6.04\\%<= Stong mixing 5Z: 6.04 <= A italusˇ dans la liste des TBE ? $^3B_2 (\pi \rightarrow \pi^\star)$ &3.50 &3.49 &3.50 &3.50 &3.50& 3.50& \hl{xxx}\\ %N122 $^3A_1 (\pi \rightarrow \pi^\star)$ &4.74 &4.74 &4.74 &4.75 &4.74& 4.74& 4.75\\% 5Z: 4.75 \hline \end{tabular} \begin{flushleft} %$^a${Significant mixing.} \end{flushleft} \end{small} \end{table} \clearpage \subsection{Acrolein, butadiene, and glyoxal} \begin{sidewaystable}[htp] \caption{\small CC3 vertical transition energies of acrolein, butadiene, and glyoxal using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S3} \begin{small} \begin{tabular}{l|ccccccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & \multicolumn{2}{c}{\AVQZ} &{\DAVQZ} &{\AVFZ}\\ & FC & FC &FC & FC & Full & FC & FC \\ \hline & \multicolumn{6}{c}{Acrolein} \\ \hline $^1A'' (n \rightarrow \pi^\star)$ &3.83 &3.77 &3.74 &3.75 &3.74\\ $^1A' (\pi \rightarrow \pi^\star)$ &6.83 &6.67 &6.65 &6.65 &6.65\\ $^1A'' (n \rightarrow \pi^\star)$ &6.94 &6.75 &6.75 &6.77 &6.76\\ $^1A' (n \rightarrow 3s)$ &7.22 &6.99 &7.07 &7.11 &7.11\\ $^3A'' (n \rightarrow \pi^\star)$ &3.55 &3.47 &3.46 &3.47 &3.46\\ $^3A' (\pi \rightarrow \pi^\star)$ &3.94 &3.95 &3.94 &3.95 &3.94\\ $^3A' (\pi \rightarrow \pi^\star)$ &6.25 &6.22 &6.19 &6.20 &6.19\\ $^3A'' (n \rightarrow \pi^\star)$ &6.81 &6.60 &6.61 &6.63 &6.62\\ \hline & \multicolumn{6}{c}{Butadiene} \\ \hline $^1B_u (\pi \rightarrow \pi^\star)$ &6.41 &6.25 &6.22 &6.21 &6.22\\ $^1B_g (\pi \rightarrow 3s)$ &6.53 &6.26 &6.33 &6.35 &6.36\\ $^1A_g (\pi \rightarrow \pi^\star)$ &6.73 &6.68 &6.67 &6.67 &6.67& 6.67\\ $^1A_u (\pi \rightarrow 3p)$ &6.87 &6.57 &6.64 &6.66 &6.67\\ $^1A_u (\pi \rightarrow 3p)$ &6.93 &6.73 &6.80 &6.82 &6.83\\ $^1B_u (\pi \rightarrow 3p)$ &7.98 &7.86 &7.68 &7.54 &7.55\\ $^3B_u (\pi \rightarrow \pi^\star)$ &3.35 &3.36 &3.36 &3.37 &3.36\\ $^3A_g (\pi \rightarrow \pi^\star)$ &5.22 &5.21 &5.20 &5.21 &5.20\\ $^3B_g (\pi \rightarrow 3s)$ &6.46 &6.20 &6.28 &6.30 &6.31\\ \hline & \multicolumn{6}{c}{Glyoxal} \\ \hline $^1A_u (n \rightarrow \pi^\star)$ &2.94 &2.90 &2.88 &2.88 &2.87& 2.88& 2.88\\ $^1B_g (n \rightarrow \pi^\star)$ &4.34 &4.30 &4.27 &4.27 &4.27& 4.27& \\ $^1A_g (n,n \rightarrow \pi^\star,\pi^\star)$&6.74 &6.70 &6.76 &6.76 &6.74& 6.76& 6.75 \\ $^1B_g (n \rightarrow \pi^\star)$ &6.81 &6.59 &6.58 &6.59 &6.58& 6.58& \\ $^1B_u (n \rightarrow3p)$ &7.72 &7.55 &7.67 &7.72 &7.73& 7.72& 7.74\\ $^3A_u (n \rightarrow \pi^\star)$ &2.55 &2.49 &2.49 &2.49 &2.49& 2.49& 2.50\\ $^3B_g (n \rightarrow \pi^\star)$ &3.97 &3.91 &3.90 &3.91 &3.90& 3.91& \\ $^3B_u (\pi \rightarrow \pi^\star)$ &5.22 &5.20 &5.17 &5.18 &5.17& 5.18& 5.19\\ $^3A_g (\pi \rightarrow \pi^\star)$ &6.35 &6.34 &6.30 &6.31 &6.30& 6.31& 6.31\\ \hline \end{tabular} \end{small} \end{sidewaystable} \clearpage \subsection{Acetone, cyanoformaldehyde, isobutene, propynal, thioacetone, and thiopropynal} \begin{table}[htp] \caption{\small CC3 vertical transition energies of acetone, cyanoformaldehyde, isobutene, propynal, thioacetone, and thiopropynal using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S4} \begin{small} \begin{tabular}{l|cccccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & \multicolumn{2}{c}{\AVQZ} &{\DAVQZ} \\ & FC & FC &FC & FC & Full & FC\\ \hline & \multicolumn{6}{c}{Acetone} \\ \hline $^1A_2 (n \rightarrow \pi^\star)$ &4.55 &4.50 &4.48 &4.49 &4.48\\ $^1B_2 (n \rightarrow 3s)$ &6.65 &6.31 &6.43 &6.48 &6.49\\ $^1A_2 (n \rightarrow 3p)$ &7.83 &7.37 &7.45 &7.48 &7.49\\ $^1A_1 (n \rightarrow 3p)$ &7.81 &7.39 &7.48 &7.52 &7.53\\ $^1B_2 (n \rightarrow 3p)$ &7.87 &7.56 &7.59 &7.60 &7.61\\ $^3A_2 (n \rightarrow \pi^\star)$ &4.21 &4.16 &4.15 &4.17 &4.16\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &6.32 &6.31 &6.28 &6.30 &6.28\\ \hline & \multicolumn{6}{c}{Cyanoformaldehyde} \\ \hline $^1A'' (n \rightarrow \pi^\star)$ &3.91 &3.86 &3.83 &3.84 &3.83 &3.84\\ $^1A'' (\pi \rightarrow \pi^\star)$ &6.64 &6.51 &6.42 &6.41 &6.41 &6.41\\ $^3A'' (n \rightarrow \pi^\star)$ &3.53 &3.47 &3.46 &3.47 &3.46 &3.47\\ $^3A' (\pi \rightarrow \pi^\star)$ &5.07 &5.03 &5.01 &5.02 &5.01 &5.02\\ \hline & \multicolumn{6}{c}{Isobutene} \\ \hline $^1B_1 (\pi \rightarrow 3s)$ &6.77 &6.39 &6.45 &6.47 &6.49\\ $^1A_1 (\pi \rightarrow 3p)$ &7.16 &7.00 &7.00 &6.99 &7.00\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &4.52 &4.54 &4.53 &4.54 &4.54\\ \hline & \multicolumn{6}{c}{Propynal} \\ \hline $^1A'' (n \rightarrow \pi^\star)$ &3.90 &3.85 &3.82 &3.83 &3.82 &3.83\\ $^1A'' (\pi \rightarrow \pi^\star)$ &5.69 &5.59 &5.51 &5.50 &5.50 &5.50\\ $^3A'' (n \rightarrow \pi^\star)$ &3.56 &3.50 &3.49 &3.50 &3.49 &3.50\\ $^3A' (\pi \rightarrow \pi^\star)$ &4.46 &4.40 &4.43 &4.44 &4.43 &4.44\\ \hline & \multicolumn{6}{c}{Thioacetone} \\ \hline $^1A_2 (n \rightarrow \pi^\star)$ &2.58 &2.59 &2.55 &2.56 &\\ $^1B_2 (n \rightarrow 4s)$ &5.65 &5.44 &5.55 &5.60 &\\ $^1A_1 (\pi \rightarrow \pi^\star)$ &6.09 &5.97 &5.90 &5.88 &\\ $^1B_2 (n \rightarrow 4p)$ &6.59 &6.45 &6.51 &6.52 &\\ $^1A_1 (n \rightarrow 4p)$ &6.95 &6.54 &6.61 &6.64 &6.64\\ $^3A_2 (n \rightarrow \pi^\star)$ &2.36 &2.36 &2.34 &2.35 &\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &3.45 &3.51 &3.46 &3.47 &\\ \hline & \multicolumn{5}{c}{Thiopropynal} \\ \hline $^1A'' (n \rightarrow \pi^\star)$ &2.09 &2.09 &2.05 &2.06 &2.04\\ $^3A'' (n \rightarrow \pi^\star)$ &1.84 &1.83 &1.81 &1.82 &1.81\\ \hline \end{tabular} \end{small} \end{table} \clearpage \subsection{Cyclopentadiene, furan, imidazole, pyrrole, and thiophene} \begin{table}[htp] \caption{\small CC3 vertical transition energies of furan and pyrrole using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S5} \begin{small} \begin{tabular}{l|ccccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & \multicolumn{2}{c}{{\AVQZ}} \\ & FC & FC &FC & FC & Full \\ \hline & \multicolumn{5}{c}{Furan} \\ \hline $^1A_2 (\pi \rightarrow 3s)$ &6.26 &6.00 &6.08 &6.10 &6.12\\ $^1B_2 (\pi \rightarrow \pi^\star)$ &6.50 &6.37 &6.34 &6.34 &6.34\\ $^1A_1 (\pi \rightarrow \pi^\star)$ &6.71 &6.62 &6.58 &6.58 &6.58\\ $^1B_1 (\pi \rightarrow 3p)$ &6.76 &6.55 &6.63 &6.65 &6.67\\ $^1A_2 (\pi \rightarrow 3p)$ &6.97 &6.73 &6.80 &6.82 &6.83\\ $^1B_2 (\pi \rightarrow 3p)$ &7.53 &7.39 &7.23 &7.13 &7.14\\ $^3B_2 (\pi \rightarrow \pi^\star)$ &4.28 &4.25 &4.22 &4.22 &4.22\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &5.56 &5.51 &5.48 &5.49 &5.48\\ $^3A_2 (\pi \rightarrow 3s)$ &6.18 &5.94 &6.02 &6.05 &6.07\\ $^3B_1 (\pi \rightarrow 3p)$ &6.69 &6.51 &6.59 &6.61 &6.63\\ \hline & \multicolumn{5}{c}{Pyrrole} \\ \hline $^1A_2 (\pi \rightarrow 3s)$ &5.25 &5.15 &5.24 &5.27 &\hl{XXX} \\ $^1B_1 (\pi \rightarrow 3p)$ &5.99 &5.89 &5.98 &6.01 &6.02 \\ $^1A_2 (\pi \rightarrow 3p)$ &6.27 &5.94 &6.01 &6.03 &\hl{XXX} \\ $^1B_2 (\pi \rightarrow \pi^\star)$ &6.33 &6.28 &6.25 &6.22 &6.23 \\ $^1A_1 (\pi \rightarrow \pi^\star)$ &6.43 &6.35 &6.32 &6.31 &6.31 \\ $^1B_2 (\pi \rightarrow 3p)$ &7.20 &7.00 &6.83 &6.74 &6.75 \\ $^3B_2 (\pi \rightarrow \pi^\star)$ &4.59 &4.56 &4.53 &4.53 &4.52 \\ $^3A_2 (\pi \rightarrow 3s)$ &5.22 &5.12 &5.21 &5.24 &\hl{XXX} \\ $^3A_1 (\pi \rightarrow \pi^\star)$ &5.54 &5.49 &5.46 &5.47 &5.46 \\ $^3B_1 (\pi \rightarrow 3p)$ &5.91 &5.82 &5.92 &5.95 &5.97 \\ \hline \end{tabular} \end{small} \end{table} \begin{table}[htp] \caption{\small CC3 vertical transition energies of cyclopentadiene, imidazole, and thiophene using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S6} \begin{small} \begin{tabular}{l|cccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & {{\AVQZ}} \\ & FC & FC &FC & FC \\ \hline & \multicolumn{4}{c}{Cyclopentadiene} \\ \hline $^1B_2 (\pi \rightarrow \pi^\star)$ &5.79 &5.59 &5.54 &5.53 \\ $^1A_2 (\pi \rightarrow 3s)$ &6.08 &5.70 &5.77 &5.79 \\ $^1B_1 (\pi \rightarrow 3p)$ &6.57 &6.34 &6.40 &6.42 \\ $^1A_2 (\pi \rightarrow 3p)$ &6.67 &6.39 &6.45 &6.46 \\ $^1B_2 (\pi \rightarrow 3p)$ &7.06 &6.55 &6.56 &6.55 \\ $^1A_1 (\pi \rightarrow \pi^\star)$ &6.67 &6.59 &6.57 &6.57 \\ $^3B_2 (\pi \rightarrow \pi^\star)$ &3.33 &3.32 &3.32 &3.32 \\ $^3A_1 (\pi \rightarrow \pi^\star)$ &5.16 &5.14 &5.12 &5.13 \\ $^3A_2 (\pi \rightarrow 3s)$ &6.01 &5.65 &5.73 &5.75 \\ $^3B_1 (\pi \rightarrow 3p)$ &6.51 &6.30 &6.36 &6.38 \\ \hline & \multicolumn{4}{c}{Imidazole} \\ \hline $^1A'' (\pi \rightarrow 3s)$ &5.77 &5.60 &5.71 &5.73 \\ $^1A' (\pi \rightarrow \pi^\star)$ &6.51 &6.43 &6.41 &6.41 \\ $^1A'' (n \rightarrow \pi^\star)$ &6.66 &6.42 &6.50 &6.53 \\ $^1A' (\pi \rightarrow 3p)$ &7.04 &6.93 &6.87 &6.86 \\ $^3A' (\pi \rightarrow \pi^\star)$ &4.83 &4.78 &4.75 &4.76 \\ $^3A'' (\pi \rightarrow 3s)$ &5.72 &5.57 &5.67 &5.70 \\ $^3A' (\pi \rightarrow \pi^\star)$ &5.88 &5.78 &5.74 &5.75 \\ $^3A'' (n \rightarrow \pi^\star)$ &6.48 &6.37 &6.33 &6.33 \\ \hline & \multicolumn{4}{c}{Thiophene} \\ \hline $^1A_1 (\pi \rightarrow \pi^\star)$ &5.79 &5.70 &5.65 &5.64\\ $^1B_2 (\pi \rightarrow \pi^\star)$ &6.23 &6.05 &5.96 &5.94\\ $^1A_2 (\pi \rightarrow 3s)$ &6.26 &6.07 &6.14 &6.16\\ $^1B_1 (\pi \rightarrow 3p)$ &6.18 &6.19 &6.14 &6.11\\ $^1A_2 (\pi \rightarrow 3p)$ &6.32 &6.33 &6.25 &6.22\\ $^1B_1 (\pi \rightarrow 3s)$ &6.62 &6.42 &6.50 &6.53\\ $^1B_2 (\pi \rightarrow 3p)$ &7.45 &7.45 &7.29 &7.18\\ $^1A_1 (\pi \rightarrow \pi^\star)$ &7.50 &7.41 &7.35 &7.33\\ $^3B_2 (\pi \rightarrow \pi^\star)$ &3.95 &3.96 &3.94 &3.93\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &4.90 &4.82 &4.77 &4.77\\ $^3B_1 (\pi \rightarrow 3p)$ &6.00 &6.01 &5.95 &5.92\\ $^3A_2 (\pi \rightarrow 3s)$ &6.20 &6.01 &6.09 &5.99\\ \hline \end{tabular} \end{small} \end{table} \clearpage \subsection{Benzene, pyrazine, and tetrazine} \begin{table}[htp] \caption{\small CC3 vertical transition energies of benzene using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S7} \begin{small} \begin{tabular}{l|cccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & {\AVQZ} \\ & FC & FC &FC & FC \\ \hline & \multicolumn{4}{c}{Benzene} \\ \hline $^1B_{2u} (\pi \rightarrow \pi^\star)$ &5.13 &5.11 &5.09 &5.09\\ $^1B_{1u} (\pi \rightarrow \pi^\star)$ &6.68 &6.50 &6.44 &6.43\\ $^1E_{1g} (\pi \rightarrow 3s)$ &6.75 &6.46 &6.52 &6.54\\ $^1A_{2u} (\pi \rightarrow 3p)$ &7.24 &7.02 &7.08 &7.10\\ $^1E_{2u} (\pi \rightarrow 3p)$ &7.34 &7.09 &7.15 &7.16\\ $^3B_{1u} (\pi \rightarrow \pi^\star)$ &4.18 &4.19 &4.18 &4.19\\ $^3E_{1u}(\pi \rightarrow \pi^\star)$ &4.95 &4.89 &4.86 &4.87\\ $^3B_{2u} (\pi \rightarrow \pi^\star)$ &6.06 &5.86 &5.81 &5.81\\ \hline \end{tabular} \end{small} \end{table} \clearpage \begin{table}[htp] \caption{\small CC3 vertical transition energies of tetrazine using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S8} \begin{small} \begin{tabular}{l|ccccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & \multicolumn{2}{c}{{\AVQZ}} \\ & FC & FC &FC & FC & Full \\ \hline & \multicolumn{5}{c}{Pyrazine} \\ \hline $^1B_{3u} (n \rightarrow \pi^\star)$ & 4.28 &4.19 &4.14 &4.14\\ $^1A_{u} (n \rightarrow \pi^\star)$ & 5.08 &4.98 &4.97 &4.98\\ $^1B_{2u} (\pi \rightarrow \pi^\star)$ & 5.10 &5.07 &5.03 &5.02\\ $^1B_{2g} (n \rightarrow \pi^\star)$ & 5.86 &5.78 &5.71 &5.71\\ $^1A_{g} (n \rightarrow 3s)$ & 6.74 &6.54 &6.66 &6.70& 6.71\\ $^1B_{1g} (n \rightarrow \pi^\star)$ & 6.87 &6.75 &6.73 &6.73\\ $^1B_{1u} (\pi \rightarrow \pi^\star)$ & 7.10 &6.92 &6.86 &6.85& 6.85\\ $^1B_{1g} (n \rightarrow 3p)$ & 7.36 &7.13 &7.20 &7.23\\ $^1B_{2u} (n \rightarrow 3p)$ & 7.39 &7.14 &7.25 &7.29\\ $^1B_{1u} (\pi \rightarrow 3s)$ & 7.56 &7.38 &7.45 &7.48& 7.49\\ $^1B_{1u} (\pi \rightarrow \pi^\star)$ & 8.19 &7.99 &7.94 &7.93& 7.93\\ $^3B_{3u} (n \rightarrow \pi^\star)$ & 3.68 &3.60 &3.59 &3.59\\ $^3B_{1u} (\pi \rightarrow \pi^\star)$ & 4.39 &4.40 &4.39 &4.40& 4.39\\ $^3B_{2u} (\pi \rightarrow \pi^\star)$ & 4.56 &4.46 &4.40 &4.40\\ $^3A_{u} (n \rightarrow \pi^\star)$ & 5.05 &4.93 &4.93 &4.94\\ $^3B_{2g} (n \rightarrow \pi^\star)$ & 5.18 &5.11 &5.08 &5.09\\ $^3B_{1u} (\pi \rightarrow \pi^\star)$ & 5.38 &5.32 &5.29 &5.29& 5.28\\ \hline & \multicolumn{5}{c}{Tetrazine} \\ \hline $^1B_{3u} (n \rightarrow \pi^\star)$ & 2.53 &2.49 &2.46 &2.45 &2.45\\ $^1A_{u} (n \rightarrow \pi^\star)$ & 3.75 &3.69 &3.67 &3.68 &3.67\\ $^1A_{g} (n,n \rightarrow \pi^\star, \pi^\star)$ & 6.22 &6.22 &6.21 &6.19 &6.17\\ $^1B_{1g} (n \rightarrow \pi^\star)$ & 5.01 &4.97 &4.91 &4.90 &4.88\\ $^1B_{2u} (\pi \rightarrow \pi^\star)$ & 5.29 &5.27 &5.23 &5.22 &5.21\\ $^1B_{2g} (n \rightarrow \pi^\star)$ & 5.56 &5.53 &5.46 &5.46 &5.45\\ $^1A_{u} (n \rightarrow \pi^\star)$ & 5.61 &5.59 &5.52 &5.52 &5.50\\ $^1B_{3g} (n,n \rightarrow \pi^\star, \pi^\star)$ & 7.64 &7.62 &7.62 &7.60 &7.58\\ $^1B_{2g} (n \rightarrow \pi^\star)$ & 6.24 &6.17 &6.13 &6.13 &6.10\\ $^1B_{1g} (n \rightarrow \pi^\star)$ & 7.04 &6.98 &6.92 &6.92 &6.91\\ $^3B_{3u} (n \rightarrow \pi^\star)$ & 1.87 &1.86 &1.85 &1.86 &1.85\\ $^3A_{u} (n \rightarrow \pi^\star)$ & 3.48 &3.43 &3.44 &3.45 &3.43\\ $^3B_{1g} (n \rightarrow \pi^\star)$ & 4.25 &4.23 &4.20 &4.21 &4.18\\ $^3B_{1u} (\pi \rightarrow \pi^\star)$ & 4.54 &4.54 &4.54 &4.54 &4.53\\ $^3B_{2u} (\pi \rightarrow \pi^\star)$ & 4.65 &4.58 &4.52 &4.52 &4.51\\ $^3B_{2g} (n \rightarrow \pi^\star)$ & 5.11 &5.09 &5.05 &5.05 &5.04\\ $^3A_{u} (n \rightarrow \pi^\star)$ & 5.17 &5.15 &5.11 &5.11 &5.10\\ $^3B_{3g} (n,n \rightarrow \pi^\star, \pi^\star)$ & 7.35 &7.33 &7.35 &7.34 &7.32\\ $^3B_{1u} (\pi \rightarrow \pi^\star)$ & 5.51 &5.46 &5.42 &5.43 &5.42\\ \hline \end{tabular} \end{small} \end{table} \clearpage \subsubsection{Pyridazine, pyridine, pyrimidine and triazine} \begin{table}[htp] \caption{\small CC3 vertical transition energies of pyridazine and pyridine using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S9} \begin{small} \begin{tabular}{l|cccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & {\AVQZ} \\ & FC & FC &FC & FC \\ \hline & \multicolumn{4}{c}{Pyridazine} \\ \hline $^1B_1 (n \rightarrow \pi^\star)$ &3.95 &3.86 &3.83 &\\ $^1A_2 (n \rightarrow \pi^\star)$ &4.49 &4.39 &4.37 &\\ $^1A_1 (\pi \rightarrow \pi^\star)$ &5.36 &5.33 &5.29 &5.29\\ $^1A_2 (n \rightarrow \pi^\star)$ &5.88 &5.80 &5.74 &\\ $^1B_2 (n \rightarrow 3s)$ &6.26 &6.06 &6.17 &\\ $^1B_1 (n \rightarrow \pi^\star)$ &6.51 &6.41 &6.37 &\\ $^1B_2 (\pi \rightarrow \pi^\star)$ &6.96 &6.79 &6.74 &\\ $^3B_1 (n \rightarrow \pi^\star)$ &3.27 &3.20 &3.19 &3.20\\ $^3A_2 (n \rightarrow \pi^\star)$ &4.19 &4.11 &4.11 &\\ $^3B_2 (\pi \rightarrow \pi^\star)$ &4.39 &4.39 &4.38 &\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &4.93 &4.87 &4.83 &4.82\\ \hline & \multicolumn{4}{c}{Pyridine} \\ \hline $^1B_1 (n \rightarrow \pi^\star)$ &5.12 &5.01 &4.96\\ $^1B_2 (\pi \rightarrow \pi^\star)$ &5.23 &5.21 &5.17\\ $^1A_2 (n \rightarrow \pi^\star)$ &5.55 &5.41 &5.40\\ $^1A_1 (\pi \rightarrow \pi^\star)$ &6.84 &6.64 &6.63\\ $^1A_1 (n \rightarrow 3s)$ &6.92 &6.71 &6.76\\ $^1A_2 (\pi \rightarrow 3s)$ &6.98 &6.74 &6.81\\ $^1B_2 (\pi \rightarrow \pi^\star)$ &7.50 &7.40 &7.35/7.38\\ $^1B_1 (\pi \rightarrow 3p)$ &7.54 &7.32 &7.38\\ $^1A_1 (\pi \rightarrow \pi^\star)$ &7.56 &7.34 &7.39\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &4.33 &4.34 &4.33\\ $^3B_1 (n \rightarrow \pi^\star)$ &4.57 &4.47 &4.46& 4.47\\ $^3B_2 (\pi \rightarrow \pi^\star)$ &4.92 &4.83 &4.79\\ $^3A_1 (\pi \rightarrow \pi^\star)$ &5.14 &5.08 &5.05\\ $^3A_2 (n \rightarrow \pi^\star)$ &5.51 &5.37 &5.35\\ $^3B_2 (\pi \rightarrow \pi^\star)$ &6.46 &6.30 &6.25\\ \hline \end{tabular} \end{small} \end{table} \clearpage \begin{table}[htp] \caption{\small CC3 vertical transition energies of pyrimidine and triazine using various atomic basis sets. FC stands for frozen core. All values are in eV.} \label{Table-S10} \begin{small} \begin{tabular}{l|cccc} \hline & {\Pop} & {\AVDZ} & {\AVTZ} & {\AVQZ} \\ & FC & FC &FC & FC \\ \hline & \multicolumn{4}{c}{Pyrimidine} \\ \hline $^1B_1 (n \rightarrow \pi^\star)$ & 4.58 &4.48 &4.44 &\\ $^1A_2 (n \rightarrow \pi^\star)$ & 4.99 &4.89 &4.86 &\\ $^1B_2 (\pi \rightarrow \pi^\star)$ & 5.47 &5.44 &5.41 &\\ $^1A_2 (n \rightarrow \pi^\star)$ & 6.07 &5.98 &5.93 &\\ $^1B_1 (n \rightarrow \pi^\star)$ & 6.39 &6.29 &6.26 &\\ $^1B_2 (n \rightarrow 3s)$ & 6.81 &6.61 &6.72 &6.76\\ $^1A_1 (\pi \rightarrow \pi^\star)$ & 7.08 &6.93 &6.87 &6.86\\ $^3B_1 (n \rightarrow \pi^\star)$ & 4.20 &4.12 &4.10 &4.11\\ $^3A_1 (\pi \rightarrow \pi^\star)$ & 4.55 &4.56 &4.55 &4.56\\ $^3A_2 (n \rightarrow \pi^\star)$ & 4.77 &4.67 &4.66 &4.67\\ $^3B_2 (\pi \rightarrow \pi^\star)$ & 5.08 &5.00 &4.96 &4.96\\ \hline & \multicolumn{4}{c}{Triazine} \\ \hline $^1A_1'' (n \rightarrow \pi^\star)$ & 4.85 &4.76 &4.73 &4.74\\ $^1A_2'' (n \rightarrow \pi^\star)$ & 4.84 &4.78 &4.74 &4.74\\ $^1E'' (n \rightarrow \pi^\star)$ & 4.89 &4.82 &4.78 &4.79\\ $^1A_2' (\pi \rightarrow \pi^\star)$ & 5.84 &5.81 &5.78 &5.78\\ $^1A_1' (\pi \rightarrow \pi^\star)$ & 7.45 &7.31 &7.24 &7.23\\ $^1E' (n \rightarrow 3s)$ & 7.44 &7.24 &7.35 &7.39\\ $^1E'' (n \rightarrow \pi^\star)$ & 7.89 &7.82 &7.79 &7.78\\ $^1E' (\pi \rightarrow \pi^\star)$ & 8.12 &7.97 &7.92 &7.92\\ $^3A_2'' (n \rightarrow \pi^\star)$ & 4.40 &4.35 &4.33 &4.34\\ $^3E'' (n \rightarrow \pi^\star)$ & 4.59 &4.52 &4.51 &4.51\\ $^3A_1'' (n \rightarrow \pi^\star)$ & 4.87 &4.78 &4.75 &4.76\\ $^3A_1' (\pi \rightarrow \pi^\star)$ & 4.88 &4.88 &4.88 &4.89\\ $^3E' (\pi \rightarrow \pi^\star)$ & 5.70 &5.64 &5.61 &5.61\\ $^3A_2' (\pi \rightarrow \pi^\star)$ & 6.85 &6.69 &6.63 &6.62\\ \hline \end{tabular} \end{small} \end{table} \clearpage \clearpage \section{Multi-reference results} \subsection{Basis set effects} \begin{table}[htp] \caption{\small Vertical transition energies of cyanoacetylene, cyanogen, and diacetylene using various atomic basis sets and multi-reference methods. All values are in eV and have been obtained with within the FC approximation. The CASPT2 calculations are performed with a level shift of 0.3 and a IPEA of 0.25. Pop, AVDZ, AVTZ, and AVQZ respectively stand for {\Pop}, {\AVDZ}, {\AVTZ}, and {\AVQZ}. } \label{Table-S1b} \begin{footnotesize} \begin{tabular}{l|cccccccccccc} \hline & \multicolumn{4}{c}{CASPT2(8,8)} & \multicolumn{4}{c}{PC-NEVPT2(8,8)} & \multicolumn{4}{c}{SC-NEVPT2(8,8)} \\ & Pop &AVDZ & AVTZ & AVQZ & Pop &AVDZ & AVTZ & AVQZ& Pop &AVDZ & AVTZ & AVQZ \\ \hline & \multicolumn{12}{c}{Cyanoacetylene} \\ \hline $^1\Sigma^-$ & & 6.00 & 5.86 & & & 5.93 & 5.78 & & & 5.98 & 5.83 & \\ $^1\Delta$ & & 6.26 & 6.13 & & & 6.22 & 6.10 & & & 6.27 & 6.14 & \\ $^3\Sigma^+$ & & 4.47 & 4.45 & & & 4.46 & 4.45 & & & 4.51 & 4.49 & \\ $^3\Delta$ & & 5.30 & 5.21 & & & 5.28 & 5.19 & & & 5.31 & 5.23 & \\ \hline & \multicolumn{12}{c}{Cyanogen} \\ \hline $^1\Sigma_u^-$ & 6.63 & 6.56 & 6.40 & 6.37 & 6.56 & 6.49 & 6.32 & 6.29 & 6.61 & 6.54 & 6.37 & 6.34 \\ $^1\Delta_u$ & 6.93 & 6.84 & 6.70 & 6.66 & 6.91 & 6.81 & 6.66 & 6.63 & 6.95 & 6.86 & 6.71 & 6.68 \\ $^3\Sigma_u^+$ & 4.91 & 4.89 & 4.86 & 4.86 & 4.92 & 4.91 & 4.88 & 4.89 & 4.96 & 4.95 & 4.92 & 4.93 \\ $^1\Sigma_u^-$[F] & & 5.23 & 5.07 & & & 5.14 & 4.97 & & & 5.17 & 5.01 & \\ \hline & \multicolumn{12}{c}{Diacetylene} \\ \hline $^1\Sigma_u^-$ & & 5.56 & 5.43 & & & 5.47 & 5.33 & & & 5.53 & 5.39 & \\ $^1\Delta_u$ & & 5.80 & 5.68 & & & 5.73 & 5.61 & & & 5.78 & 5.67 & \\ $^3\Sigma_u^+$ & & 4.12 & 4.11 & & & 4.09 & 4.08 & & & 4.14 & 4.13 & \\ $^3\Delta_u$ & & 4.89 & 4.81 & & & 4.86 & 4.78 & & & 4.90 & 4.82 & \\ \hline \end{tabular} \end{footnotesize} \end{table} \clearpage \subsection{Active Spaces} \clearpage \section{sCI results} \begin{landscape} \begin{footnotesize} \begin{longtable}{p{3.5cm}p{3.5cm}p{2cm}p{1.2cm}p{2.8cm}p{2cm}p{1.2cm}p{2.8cm}} \caption{ Vertical excitations (in eV) for various states of the studied molecules computed with an extrapolated sCI method (exFCI). The number of determinants $N_\text{det}$ of the largest sCI wave functions and their corresponding excitation energies are also reported. The extrapolation error is estimated as the difference in excitation energy between the largest sCI wave function and its corresponding extrapolated value. \label{tab:sCI}} \\ \hline Molecule & Transition & \mc{3}{c}{\Pop} & \mc{3}{c}{\AVDZ} \\ \cline{3-5} \cline{6-8} & & $\Ndet$ & sCI & exFCI & $\Ndet$ & sCI & exFCI \\ \hline \endfirsthead \hline Molecule & Transition & \mc{3}{c}{\Pop} & \mc{3}{c}{\AVDZ} \\ \cline{3-5} \cline{6-8} & & $\Ndet$ & sCI & exFCI & $\Ndet$ & sCI & exFCI \\ \hline \endhead \hline \multicolumn{8}{r}{{Continued on next page}} \\ \endfoot \hline \endlastfoot Acetone & $^1A_2 (\Val; n \ra \pis)$ & $26\,526\,782$ & $4.55$ & $4.60\pm0.05$ \\ % & $^1B_2 (\Ryd; n \ra 3s)$ & $25\,1675\,94$ & $6.91$ & $6.83\pm0.08$ \\ %TO BE CHECKED !!!!! % & $^1A_2 (\Ryd; n \ra 3p)$ & $$ & $$ & $$ \\ % & $^1A_1 (\Ryd; n \ra 3p)$ & $$ & $$ & $$ \\ % & $^1B_2 (\Ryd; n \ra 3p)$ & $$ & $$ & $$ \\ & $^3A_2 (\Val; n \ra \pis)$ & $26\,553\,941$ & $4.22$ & $4.18\pm0.04$ \\ % & $^3A_1 (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ Acrolein & $^1A'' (\Val; n \ra \pis)$ & $23\,273\,572$ & $3.84$ & $3.85\pm0.01$ \\ % & $^1A' (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ % & $^1A'' (\Val; n \ra \pis)$ & $$ & $$ & $$ \\ % & $^1A' (\Ryd; n \ra 3s)$ & $$ & $$ & $$ \\ & $^3A'' (\Val; n \ra \pis)$ & $26\,531\,491$ & $3.59$ & $3.60\pm0.01$ & $15\,827\,189$ & $3.58$ & $3.51\pm0.07$ \\ & $^3A' (\Val; \pi \ra \pis)$ & $37\,480\,261$ & $4.01$ & $3.98\pm0.03$ & $15\,827\,189$ & $4.05$ & $3.96\pm0.09$ \\ % & $^3A' (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ % & $^3A'' (\Ryd; \pi \ra 3s)$ & $$ & $$ & $$ \\ Butadiene & $^1B_u (\Val; \pi \ra \pis)$ & $20\,552\,493$ & $6.43$ & $6.41\pm0.02$ \\ % & $^1B_g (\Ryd; \pi \ra 3s)$ & $$ & $$ & $$ \\ % & $^1A_g (\Val; \pi \ra \pis)$ & $92\,506\,300$ & $6.59$ & $6.55\pm0.04$ % & $59\,594\,588$ & $6.58$ & $6.51\pm0.07$ \\ % & $^1A_u (\Ryd; \pi \ra 3p)$ & $$ & $$ & $$ \\ & $^1A_u (\Ryd; \pi \ra 3p)$ & $20\,552\,493$ & $6.96$ & $6.95\pm0.01$ & $12\,521\,242$ & $6.72$ & $6.72\pm0.00$ \\ % & $^1B_u (\Ryd; \pi \ra 3p)$ & $$ & $$ & $$ \\ & $^3B_u (\Val; \pi \ra \pis)$ & $49\,847\,526$ & $3.40$ & $3.37\pm0.03$ \\ & $^3A_g (\Val; \pi \ra \pis)$ & & & & $17\,235\,280$ & $6.29$ & $6.21\pm0.08$ \\ & $^3B_g (\Val; \pi \ra 3s)$ & $49\,847\,526$ & $6.43$ & $6.40\pm0.03$ \\ Cyanoacetylene & $^1\Sigma^- (\Val; \pi \ra \pis)$ & $21\,269\,249$ & $6.01$ & $6.02\pm0.01$ & $11\,023\,351$ & $5.93$ & $5.84\pm0.09$ \\ & $^1\Delta (\Val; \pi \ra \pis)$ & $21\,269\,249$ & $6.29$ & $6.28\pm0.01$ & $11\,023\,351$ & $6.19$ & $6.14\pm0.05$ \\ & $^3\Sigma^+ (\Val; \pi \ra \pis)$ & $18\,198\,954$ & $4.48$ & $4.45\pm0.03$ & $25\,646\,703$ & $4.47$ & $4.41\pm0.06$ \\ & $^3\Delta (\Val; \pi \ra \pis)$ & $18\,198\,954$ & $5.35$ & $5.32\pm0.03$ & $25\,646\,703$ & $5.28$ & $5.20\pm0.08$ \\ & $^1A'' [\Fl] (\Val; \pi \ra \pis)$ & $104\,485\,975$ & $3.70$ & $3.67\pm0.03$ & $62\,248\,690$ & $3.61$ & $3.50\pm0.02$ \\ Cyanoformaldehyde & $^1A'' (\Val; n \ra \pis)$ & $17\,778\,047$ & $3.94$ & $3.92\pm0.02$ & $19\,020\,785$ & $3.93$ & $3.98\pm0.05$ \\ & $^1A'' (\Val; \pi \ra \pis)$ & $17\,778\,047$ & $6.67$ & $6.60\pm0.07$ & $19\,020\,785$ & $6.57$ & $6.58\pm0.01$ \\ & $^3A'' (\Val; n \ra \pis)$ & $21\,011\,221$ & $3.54$ & $3.48\pm0.06$ & $48\,532\,729$ & $3.51$ & $3.52\pm0.01$ \\ & $^3A' (\Val; \pi \ra \pis)$ & & & & $48\,5327\,29$ & $5.10$ & $5.07\pm0.03$ \\ Cyanogen & $^1\Sigma_u^- (\Val; \pi \ra \pis)$ & $12\,1991\,55$ & $6.61$ & $6.58\pm0.03$ & $20\,9495\,13$ & $6.52$ & $6.44\pm0.08$ \\ & $^1\Delta_u (\Val; \pi \ra \pis)$ & $12\,1991\,55$ & $6.89$ & $6.87\pm0.02$ & $20\,9495\,13$ & $6.78$ & $6.74\pm0.04$ \\ & $^3\Sigma_u^+ (\Val; \pi \ra \pis)$ & $34\,1277\,36$ & $4.97$ & $4.91\pm0.06$ & $25\,7606\,68$ & $4.94$ & $4.87\pm0.07$ \\ & $^1\Sigma_u^- [\Fl] (\Val; \pi \ra \pis)$ & $21\,4163\,04$ & $5.36$ & $5.31\pm0.05$ & $28\,8841\,38$ & $5.17$ & $5.26\pm0.09$ \\ Cyclopropenone & $^1B_1 (\Val; n \ra \pis)$ & $48\,8976\,96$ & $4.40$ & $4.38\pm0.02$ \\ & $^1A_2 (\Val; n \ra \pis)$ & $24\,5411\,16$ & $5.70$ & $5.64\pm0.06$ \\ % & $^1B_2 (\Ryd; n \ra 3s)$ & $$ & $$ & $$ \\ % & $^1B_2 (\Val; \pi \ra \pis$) & $$ & $$ & $$ \\ % & $^1B_2 (\Ryd; n \ra 3p)$ & $$ & $$ & $$ \\ % & $^1A_1 (\Ryd; n \ra 3p)$ & $$ & $$ & $$ \\ % & $^1A_1 (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ & $^3B_1 (\Val; n \ra \pis)$ & $24\,008\,328$ & $4.07$ & $4.00\pm0.07$ \\ & $^3B_2 (\Val; \pi \ra \pis)$ & $48\,311\,362$ & $4.95$ & $4.95\pm0.00$ \\ % & $^3A_2 (\Val; n \ra \pis)$ & $$ & $$ & $$ \\ % & $^3A_1 (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ Cyclopropenethione & $^1A_2 (\Val; n \ra \pis)$ & $39\,385\,657$ & $3.46$ & $3.45\pm0.01$ \\ & $^1B_1 (\Val; n \ra \pis)$ & $39\,385\,657$ & $3.50$ & $3.44\pm0.05$ \\ & $^1B_2 (\Val; \pi \ra \pis)$ & $39\,385\,657$ & $4.68$ & $4.59\pm0.09$ \\ % & $^1B_2 (\Ryd; n \ra 3s)$ & $$ & $$ & $$ \\ % & $^1A_1 (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ % & $^1B_2 (\Ryd; n \ra 3p)$ & $$ & $$ & $$ \\ & $^3A_2 (\Val; n \ra \pis)$ & $23\,904\,962$ & $3.32$ & $3.29\pm0.03$ \\ % & $^3B_1 (\Val; n \ra \pis)$ & $$ & $$ & $$ \\ & $^3B_2 (\Val; \pi \ra \pis)$ & $23\,904\,962$ & $4.06$ & $4.03\pm0.03$ \\ % & $^3A_1 (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ Diacetylene & $^1\Sigma_u^- (\Val; \pi \ra \pis)$ & $18\,955\,451$ & $5.58$ & $5.52\pm0.06$ & $19\,192\,556$ & $5.45$ & $5.47\pm0.02$ \\ & $^1\Delta_u (\Val; \pi \ra \pis)$ & $18\,955\,451$ & $5.85$ & $5.84\pm0.01$ & $19\,192\,556$ & $5.45$ & $5.69\pm0.02$ \\ & $^3\Sigma_u^+ (\Val; \pi \ra \pis)$ & $13\,777\,757$ & $4.11$ & $4.04\pm0.07$ & $26\,668\,471$ & $4.11$ & $4.07\pm0.04$ \\ & $^3\Delta_u (\Val; \pi \ra \pis)$ & $13\,777\,757$ & $4.93$ & $4.94\pm0.01$ & $26\,668\,471$ & $4.87$ & $4.85\pm0.02$ \\ Glyoxal & $^1A_u (\Val; n \ra \pis)$ & $51\,656\,090$ & $2.96$ & $2.93\pm0.03$ & $34\,125\,394$ & $2.94$ & $2.93\pm0.01$ \\ & $^1B_g (\Val; n \ra \pis)$ & $24\,394\,242$ & $4.34$ & $4.28\pm0.06$ \\ % & $^1A_g (\Val; n,n \ra \pis,\pis)$ & $118\,275\,835$ & $5.69$ & $5.60\pm0.09$ \\ % & $^1B_g (\Val; n \ra \pis)$ & $$ & $$ & $$ \\ % & $^1B_u (\Ryd; n \ra 3p)$ & $$ & $$ & $$ \\ & $^3A_u (\Val; n \ra \pis)$ & $47\,693\,908$ & $2.58$ & $2.54\pm0.04$ \\ % & $^3B_g (\Val; n \ra \pis)$ & $$ & $$ & $$ \\ % & $^3B_u (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ % & $^3A_g (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ Isobutene & $^1B_1 (\Ryd; \pi \ra 3s)$ & $28\,095\,377$ & $6.86$ & $6.78\pm0.08$ \\ & $^1A_1 (\Ryd; \pi \ra 3p)$ & $59\,728\,169$ & $7.22$ & $7.16\pm0.02$ \\ & $^3A_1 \Val; (\pi \ra \pis)$ & $32\,440\,621$ & $4.54$ & $4.56\pm0.02$ \\ Methylenecyclopropene & $^1B_2 (\Val; \pi \ra \pis)$ & $51\,918\,524$ & $4.35$ & $4.32\pm0.03$ \\ % & $^1B_1 (\Ryd; \pi \ra \sigma^\star)$ & $$ & $$ & $$ \\ & $^1A_2 (\Ryd; \pi \ra 3p)$ & $25\,146\,911$ & $6.02$ & $5.92\pm0.10$ \\ & $^1A_1(\Val; \pi \ra \pis)$ & $31\,721\,213$ & $6.21$ & $6.20\pm0.01$ \\ & $^3B_2 (\Val; \pi \ra \pis)$ & $24\,379\,551$ & $3.50$ & $3.44\pm0.06$ & $43\,090\,114$ & $3.49$ & $3.45\pm0.04$ \\ & $^3A_1 (\Val; \pi \ra \pis)$ & $24\,379\,551$ & $4.77$ & $4.67\pm0.10$ & $43\,090\,114$ & $4.77$ & $4.79\pm0.02$ \\ Propynal & $^1A'' (\Val; n \ra \pis)$ & $48\,945\,252$ & $3.90$ & $3.84\pm0.06$ & $28\,249\,344$ & $3.92$ & $3.89\pm0.03$ \\ & $^1A'' (\Val; \pi \ra \pis)$ & $26\,554\,616$ & $5.72$ & $5.64\pm0.08$ & $28\,249\,344$ & $5.72$ & $5.63\pm0.09$ \\ & $^3A'' (\Val; n \ra \pis)$ & $23\,182\,284$ & $3.58$ & $3.54\pm0.04$ \\ & $^3A' (\Val; \pi \ra \pis)$ & $39\,375\,360$ & $4.52$ & $4.44\pm0.08$ \\ Thioacetone & $^1A_2 (\Val; n \ra \pis)$ & $26\,515\,070$ & $2.56$ & $2.61\pm0.05$ \\ % & $^1B_2 (\Ryd; n \ra 4s)$ & $??$ & $??$ & $5.60\pm0.04$ \\ % & $^1A_1 (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ % & $^1A_1 (\Ryd; n \ra 4p)$ & $$ & $$ & $$ \\ % & $^1B_2 (\Ryd; n \ra 4p)$ & $$ & $$ & $$ \\ & $^3A_2 (\Val; n \ra \pis)$ & $63\,669\,401$ & $2.36$ & $2.36\pm0.00$ \\ % & $^3A_1 (\Val; \pi \ra \pis)$ & $$ & $$ & $$ \\ Thiopropynal & $^1A'' (\Val; n \ra \pis)$ & $15\,782\,429$ & $2.07$ & $2.08\pm0.01$ \\ % & $^3A'' (\Val; n \ra \pis)$ & $$ & $$ & $$ \\ \end{longtable} \end{footnotesize} \begin{flushleft}\begin{footnotesize} %$^a${CI convergence too slow to provide reliable estimate.} \end{footnotesize}\end{flushleft} \end{landscape} \clearpage \section{Benchmarks} \subsection{Raw data} \subsection{MSE determined for the subsets} \begin{table}[htp] \caption{MSE in eV obtained for various subsets of transition energies.} \label{Table-SI-b2} \begin{tabular}{lcccccc} \hline Method & Singlet & Triplet & Valence & Rydberg & $n\rightarrow\pi^\star$ & $\pi\rightarrow\pi^\star$ \\ \hline CIS(D) &0.10 &0.25 &0.24 &-0.05 &0.19 &0.28 \\ {\AD} &-0.04 &0.08 &0.06 &-0.13 &-0.04 &0.14 \\ {\CCD} &-0.03 &0.11 &0.10 &-0.17 &0.01 &0.17 \\ {\STEOM} &0.06 &-0.07 &-0.04 &0.12 &-0.02 &-0.07 \\ {\CCSD} &0.15 &0.04 &0.12 &0.09 &0.19 &0.06 \\ CCSDR(3) &0.05 & &0.07 &0.02 &0.08 &0.06 \\ CCSDT-3 &0.05 & &0.06 &0.03 &0.08 &0.04 \\ {\CCT} &0.00 &0.01 &0.01 &0.00 &0.00 &0.01 \\ \hline \end{tabular} \end{table} \clearpage \section{Geometries} Below are given the cartesian coordinates of the compounds investigated in this study. These are provided in atomic units (bohr) and they have been obtained at the \CC{3}(full)/{\AVTZ} level of theory. \subsection{Acetone} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 0.18807702 C 0.00000000 2.42007545 -1.31764698 C 0.00000000 -2.42007545 -1.31764698 O 0.00000000 0.00000000 2.48269094 H 0.00000000 4.03690733 -0.05185132 H 0.00000000 -4.03690733 -0.05185132 H 1.66061256 2.48420530 -2.53995285 H -1.66061256 2.48420530 -2.53995285 H 1.66061256 -2.48420530 -2.53995285 H -1.66061256 -2.48420530 -2.53995285 \end{verbatim} \end{singlespace} \subsection{Acrolein} \begin{singlespace} \begin{verbatim} C -1.11645072 -0.68348783 0.00000000 C 1.20647847 0.83714564 0.00000000 C 3.46831059 -0.28872636 0.00000000 O -3.23666415 0.19187203 0.00000000 H -0.80613858 -2.74747338 0.00000000 H 0.98699813 2.86613511 0.00000000 H 5.20930864 0.77443560 0.00000000 H 3.60951559 -2.33000749 0.00000000 \end{verbatim} \end{singlespace} \clearpage \subsection{Benzene} \begin{singlespace} \begin{verbatim} C 0.00000000 2.63144965 0.00000000 C -2.27890225 1.31572483 0.00000000 C -2.27890225 -1.31572483 0.00000000 C 0.00000000 -2.63144965 0.00000000 C 2.27890225 -1.31572483 0.00000000 C 2.27890225 1.31572483 0.00000000 H -4.04725813 2.33668557 0.00000000 H -4.04725813 -2.33668557 0.00000000 H -0.00000000 -4.67337115 0.00000000 H 4.04725813 -2.33668557 0.00000000 H 4.04725813 2.33668557 0.00000000 H 0.00000000 4.67337115 0.00000000 \end{verbatim} \end{singlespace} \subsection{Butadiene} \begin{singlespace} \begin{verbatim} C 1.14656244 0.00000000 0.75468820 C -1.14656244 0.00000000 -0.75468820 C 3.48132647 0.00000000 -0.22482805 C -3.48132647 0.00000000 0.22482805 H 0.90770978 0.00000000 2.78883925 H -0.90770978 0.00000000 -2.78883925 H 3.77525814 0.00000000 -2.24895470 H -3.77525814 0.00000000 2.24895470 H 5.13664967 0.00000000 0.96861890 H -5.13664967 0.00000000 -0.96861890 \end{verbatim} \end{singlespace} \subsection{Cyanoacetylene} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 -3.59120182 C 0.00000000 0.00000000 -1.30693904 C 0.00000000 0.00000000 1.28880240 N 0.00000000 0.00000000 3.48692211 H 0.00000000 0.00000000 -5.59619886 \end{verbatim} \end{singlespace} \clearpage \begin{singlespace} \noindent Lowest excited state \begin{verbatim} C 1.99411175 0.00000000 2.81781077 C -0.07304269 0.00000000 1.33125774 C -0.63630126 0.00000000 -1.14556678 N -1.39755756 0.00000000 -3.26154643 H 1.90749857 0.00000000 4.87279180 \end{verbatim} \end{singlespace} \subsection{Cyanoformaldehyde} \begin{singlespace} \begin{verbatim} C -0.91561483 0.00000000 -1.22522833 C -0.01092219 0.00000000 1.39523175 N 0.64170259 0.00000000 3.48820325 O 0.50833684 0.00000000 -3.00337867 H -2.97202213 0.00000000 -1.42565674 \end{verbatim} \end{singlespace} \subsection{Cyanogen} \begin{singlespace} Ground state \begin{verbatim} C 0.00000000 0.00000000 1.30401924 C 0.00000000 0.00000000 -1.30401924 N 0.00000000 0.00000000 3.49784121 N 0.00000000 0.00000000 -3.49784121 \end{verbatim} \end{singlespace} \begin{singlespace} \noindent Lowest excited state \begin{verbatim} C 0.00000000 0.00000000 1.22784115 C 0.00000000 0.00000000 -1.22784115 N 0.00000000 0.00000000 3.56462559 N 0.00000000 0.00000000 -3.56462559 \end{verbatim} \end{singlespace} \clearpage \subsection{Cyclopentadiene} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 -2.33113051 C 0.00000000 2.22209092 -0.56871188 C 0.00000000 -2.22209092 -0.56871188 C 0.00000000 1.38514451 1.83772922 C 0.00000000 -1.38514451 1.83772922 H 1.66130504 0.00000000 -3.56414299 H -1.66130504 0.00000000 -3.56414299 H 0.00000000 4.16550405 -1.18116624 H 0.00000000 -4.16550405 -1.18116624 H 0.00000000 2.54514584 3.51352303 H 0.00000000 -2.54514584 3.51352303 \end{verbatim} \end{singlespace} \subsection{Cyclopropenone} \begin{singlespace} \begin{verbatim} C 0.00000000 1.27491826 -1.86930519 C 0.00000000 -1.27491826 -1.86930519 C 0.00000000 0.00000000 0.51814554 O 0.00000000 0.00000000 2.79326776 H 0.00000000 2.92791371 -3.05679837 H 0.00000000 -2.92791371 -3.05679837 \end{verbatim} \end{singlespace} \subsection{Cyclopropenethione} \begin{singlespace} \begin{verbatim} C 0.00000000 1.26230744 -2.86571925 C 0.00000000 -1.26230744 -2.86571925 C 0.00000000 0.00000000 -0.49233236 S 0.00000000 0.00000000 2.57821680 H 0.00000000 2.97773331 -3.95114059 H 0.00000000 -2.97773331 -3.95114059 \end{verbatim} \end{singlespace} \clearpage \subsection{Diacetylene} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 1.29447700 C 0.00000000 0.00000000 -1.29447700 C 0.00000000 0.00000000 3.58448429 C 0.00000000 0.00000000 -3.58448429 H 0.00000000 0.00000000 5.58943003 H 0.00000000 0.00000000 -5.58943003 \end{verbatim} \end{singlespace} \subsection{Furan} \begin{singlespace} \begin{verbatim} C 0.00000000 2.06365826 -0.60051250 C 0.00000000 -2.06365826 -0.60051250 C 0.00000000 1.35348578 1.86336416 C 0.00000000 -1.35348578 1.86336416 O 0.00000000 0.00000000 -2.13945332 H 0.00000000 3.86337287 -1.53765695 H 0.00000000 -3.86337287 -1.53765695 H 0.00000000 2.59168789 3.47168051 H 0.00000000 -2.59168789 3.47168051 \end{verbatim} \end{singlespace} \subsection{Glyoxal} \begin{singlespace} \begin{verbatim} C 1.21360282 0.75840215 0.00000000 C -1.21360282 -0.75840215 0.00000000 O 3.25581408 -0.26453186 0.00000000 O -3.25581408 0.26453186 0.00000000 H 0.96135276 2.81883243 0.00000000 H -0.96135276 -2.81883243 0.00000000 \end{verbatim} \end{singlespace} \clearpage \subsection{Imidazole} \begin{singlespace} \begin{verbatim} C 0.41662795 2.06006259 0.00000000 C -1.52618386 -1.62343163 0.00000000 C 1.04160471 -1.93007427 0.00000000 N -1.90345764 0.94914956 0.00000000 N 2.24215443 0.38083431 0.00000000 H 0.65501634 4.07748278 0.00000000 H -3.57500545 1.84103166 0.00000000 H -3.06363894 -2.94559167 0.00000000 H 2.08673940 -3.67001102 0.00000000 \end{verbatim} \end{singlespace} \subsection{Isobutene} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 2.70790758 C 0.00000000 0.00000000 0.18431282 C 0.00000000 2.39894572 -1.32482735 C 0.00000000 -2.39894572 -1.32482735 H 0.00000000 1.74848405 3.76691310 H 0.00000000 -1.74848405 3.76691310 H 0.00000000 4.05897160 -0.10582007 H 0.00000000 -4.05897160 -0.10582007 H 1.66026992 2.48337908 -2.55086178 H -1.66026992 2.48337908 -2.55086178 H 1.66026992 -2.48337908 -2.55086178 H -1.66026992 -2.48337908 -2.55086178 \end{verbatim} \end{singlespace} \subsection{Methylenecyclopropene} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 0.53512883 C 0.00000000 0.00000000 3.04739824 C 0.00000000 1.25042956 -1.88571561 C 0.00000000 -1.25042956 -1.88571561 H 0.00000000 2.96887531 -2.96270271 H 0.00000000 -2.96887531 -2.96270271 H 0.00000000 1.75335023 4.08608382 H 0.00000000 -1.75335023 4.08608382 \end{verbatim} \end{singlespace} \subsection{Propynal} \begin{singlespace} \begin{verbatim} C -0.78051115 0.00000000 -1.38900384 C -0.17873562 0.00000000 1.27825868 C 0.23763714 0.00000000 3.52644798 O 0.80143996 0.00000000 -3.04628328 H -2.80713069 0.00000000 -1.82768750 H 0.64026209 0.00000000 5.48853193 \end{verbatim} \end{singlespace} \subsection{Pyrazine} \begin{singlespace} \begin{verbatim} C 1.31510863 2.13188686 0.00000000 C 1.31510863 -2.13188686 0.00000000 C -1.31510863 2.13188686 0.00000000 C -1.31510863 -2.13188686 0.00000000 N 2.66620111 0.00000000 0.00000000 N -2.66620111 0.00000000 0.00000000 H 2.35234226 3.88751412 0.00000000 H 2.35234226 -3.88751412 0.00000000 H -2.35234226 3.88751412 0.00000000 H -2.35234226 -3.88751412 0.00000000 \end{verbatim} \end{singlespace} \subsection{Pyridazine} \begin{singlespace} \begin{verbatim} C 0.00000000 1.30150855 -2.31552865 C 0.00000000 -1.30150855 -2.31552865 C 0.00000000 2.49271907 0.03513416 C 0.00000000 -2.49271907 0.03513416 N 0.00000000 1.26228251 2.23104685 N 0.00000000 -1.26228251 2.23104685 H 0.00000000 4.52804172 0.19299731 H 0.00000000 -4.52804172 0.19299731 H 0.00000000 2.39011496 -4.03967703 H 0.00000000 -2.39011496 -4.03967703 \end{verbatim} \end{singlespace} \subsection{Pyridine} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 -2.66451139 C 2.25494985 0.00000000 -1.32069889 C -2.25494985 0.00000000 -1.32069889 C 2.15398594 0.00000000 1.30669632 C -2.15398594 0.00000000 1.30669632 N 0.00000000 0.00000000 2.62778932 H 0.00000000 0.00000000 -4.70641516 H 4.05768507 0.00000000 -2.27625442 H -4.05768507 0.00000000 -2.27625442 H 3.88059079 0.00000000 2.40341581 H -3.88059079 0.00000000 2.40341581 \end{verbatim} \end{singlespace} \subsection{Pyrimidine} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 2.41518350 C 0.00000000 -0.00000000 -2.60410885 C 0.00000000 2.23272561 -1.22869402 C 0.00000000 -2.23272561 -1.22869402 N 0.00000000 2.26214196 1.29619742 N 0.00000000 -2.26214196 1.29619742 H 0.00000000 0.00000000 4.45780256 H 0.00000000 0.00000000 -4.64120942 H 0.00000000 4.05149341 -2.16351748 H 0.00000000 -4.05149341 -2.16351748 \end{verbatim} \end{singlespace} \subsection{Pyrrole} \begin{singlespace} \begin{verbatim} C 0.00000000 2.11924634 0.62676569 C 0.00000000 -2.11924634 0.62676569 C 0.00000000 1.34568862 -1.85506908 C 0.00000000 -1.34568862 -1.85506908 N 0.00000000 0.00000000 2.10934391 H 0.00000000 0.00000000 4.00257355 H 0.00000000 3.97648410 1.44830201 H 0.00000000 -3.97648410 1.44830201 H 0.00000000 2.56726559 -3.47837232 H 0.00000000 -2.56726559 -3.47837232 \end{verbatim} \end{singlespace} \subsection{Tetrazine} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 2.38208164 C 0.00000000 0.00000000 -2.38208164 N 2.25673244 0.00000000 1.24973261 N -2.25673244 0.00000000 1.24973261 N 2.25673244 0.00000000 -1.24973261 N -2.25673244 0.00000000 -1.24973261 H 0.00000000 0.00000000 4.41850901 H 0.00000000 0.00000000 -4.41850901 \end{verbatim} \end{singlespace} \subsection{Thioacetone} \begin{singlespace} \begin{verbatim} C 0.00000000 0.00000000 0.68476030 C 0.00000000 2.38541696 2.20685096 C 0.00000000 -2.38541696 2.20685096 S 0.00000000 0.00000000 -2.39920303 H 0.00000000 4.04609254 1.00090614 H 0.00000000 -4.04609254 1.00090614 H 1.65894780 2.42602225 3.43712000 H -1.65894780 2.42602225 3.43712000 H 1.65894780 -2.42602225 3.43712000 H -1.65894780 -2.42602225 3.43712000 \end{verbatim} \end{singlespace} \subsection{Thiophene} \begin{singlespace} \begin{verbatim} C 0.00000000 2.33342542 -0.09858421 C 0.00000000 -2.33342542 -0.09858421 C 0.00000000 1.34371718 -2.48297725 C 0.00000000 -1.34371718 -2.48297725 S 0.00000000 0.00000000 2.17250692 H 0.00000000 4.29028016 0.44577296 H 0.00000000 -4.29028016 0.44577296 H 0.00000000 2.48760051 -4.16768392 H 0.00000000 -2.48760051 -4.16768392 \end{verbatim} \end{singlespace} \subsection{Thiopropynal} \begin{singlespace} \begin{verbatim} C -0.00382924 0.00000000 -1.25249909 C -2.27832423 0.00000000 0.15152736 C -4.26309583 0.00000000 1.29548793 S 2.81920288 0.00000000 -0.00828974 H -0.23056990 0.00000000 -3.28862183 H -5.97712967 0.00000000 2.33206931 \end{verbatim} \end{singlespace} \subsection{Triazine} \begin{singlespace} \begin{verbatim} C 0.00000000 -2.11414732 -1.22060353 C 0.00000000 0.00000000 2.44120705 C 0.00000000 2.11414732 -1.22060353 N 0.00000000 -2.24624733 1.29687150 N 0.00000000 2.24624733 1.29687150 N 0.00000000 0.00000000 -2.59374300 H 0.00000000 3.88296710 -2.24183210 H 0.00000000 -3.88296710 -2.24183210 H 0.00000000 0.00000000 4.48366420 \end{verbatim} \end{singlespace} \clearpage \section{Benchmark} \end{document}