mirror of
https://github.com/QuantumPackage/qp2.git
synced 2024-11-14 10:03:47 +01:00
130 lines
3.2 KiB
Groff
130 lines
3.2 KiB
Groff
.\" Man page generated from reStructuredText.
|
|
.
|
|
.TH "CISD" "1" "Jun 15, 2019" "2.0" "Quantum Package"
|
|
.SH NAME
|
|
cisd \- | Quantum Package >
|
|
.
|
|
.nr rst2man-indent-level 0
|
|
.
|
|
.de1 rstReportMargin
|
|
\\$1 \\n[an-margin]
|
|
level \\n[rst2man-indent-level]
|
|
level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
|
|
-
|
|
\\n[rst2man-indent0]
|
|
\\n[rst2man-indent1]
|
|
\\n[rst2man-indent2]
|
|
..
|
|
.de1 INDENT
|
|
.\" .rstReportMargin pre:
|
|
. RS \\$1
|
|
. nr rst2man-indent\\n[rst2man-indent-level] \\n[an-margin]
|
|
. nr rst2man-indent-level +1
|
|
.\" .rstReportMargin post:
|
|
..
|
|
.de UNINDENT
|
|
. RE
|
|
.\" indent \\n[an-margin]
|
|
.\" old: \\n[rst2man-indent\\n[rst2man-indent-level]]
|
|
.nr rst2man-indent-level -1
|
|
.\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
|
|
.in \\n[rst2man-indent\\n[rst2man-indent-level]]u
|
|
..
|
|
.INDENT 0.0
|
|
.INDENT 3.5
|
|
Configuration Interaction with Single and Double excitations.
|
|
.sp
|
|
This program takes a reference Slater determinant of ROHF\-like occupancy,
|
|
.sp
|
|
and performs all single and double excitations on top of it, disregarding
|
|
spatial symmetry and compute the “n_states” lowest eigenstates of that CI
|
|
matrix (see \fBdeterminants n_states\fP).
|
|
.sp
|
|
This program can be useful in many cases:
|
|
.INDENT 0.0
|
|
.IP \(bu 2
|
|
\fBGround state calculation\fP: if even after a \fBcis()\fP calculation, natural
|
|
orbitals (see \fBsave_natorb()\fP) and then \fBscf()\fP optimization, you are not sure to have the lowest scf
|
|
solution,
|
|
do the same strategy with the \fBcisd()\fP executable instead of the \fBcis()\fP\ exectuable to generate the natural
|
|
orbitals as a guess for the \fBscf()\fP\&.
|
|
.IP \(bu 2
|
|
\fBExcited states calculations\fP: the lowest excited states are much likely to
|
|
be dominanted by single\- or double\-excitations.
|
|
Therefore, running a \fBcisd()\fP will save the “n_states” lowest states within
|
|
the CISD space
|
|
in the \fI\%EZFIO\fP directory, which can afterward be used as guess wave functions
|
|
for a further multi\-state fci calculation if you specify “read_wf” = True
|
|
before running the fci executable (see \fBdeterminants read_wf\fP).
|
|
Also, if you specify “s2_eig” = True, the cisd will only retain states
|
|
having the good value S^2 value
|
|
(see \fBdeterminants expected_s2\fP and \fBdeterminants s2_eig\fP).
|
|
If “s2_eig” = False, it will take the lowest n_states, whatever
|
|
multiplicity they are.
|
|
.sp
|
|
Note: if you would like to discard some orbitals, use
|
|
qp_set_mo_class to specify:
|
|
.INDENT 2.0
|
|
.IP \(bu 2
|
|
“core” orbitals which will be always doubly occupied
|
|
.IP \(bu 2
|
|
“act” orbitals where an electron can be either excited from or to
|
|
.IP \(bu 2
|
|
“del” orbitals which will be never occupied
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.sp
|
|
Needs:
|
|
.INDENT 0.0
|
|
.INDENT 2.0
|
|
.IP \(bu 2
|
|
\fBread_wf\fP
|
|
.UNINDENT
|
|
.INDENT 2.0
|
|
.UNINDENT
|
|
.INDENT 2.0
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.sp
|
|
Calls:
|
|
.INDENT 0.0
|
|
.INDENT 2.0
|
|
.IP \(bu 2
|
|
\fBrun()\fP
|
|
.UNINDENT
|
|
.INDENT 2.0
|
|
.UNINDENT
|
|
.INDENT 2.0
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.sp
|
|
Touches:
|
|
.INDENT 0.0
|
|
.INDENT 2.0
|
|
.IP \(bu 2
|
|
\fBfock_matrix_ao_alpha\fP
|
|
.IP \(bu 2
|
|
\fBfock_matrix_ao_alpha\fP
|
|
.UNINDENT
|
|
.INDENT 2.0
|
|
.IP \(bu 2
|
|
\fBmo_coef\fP
|
|
.IP \(bu 2
|
|
\fBlevel_shift\fP
|
|
.UNINDENT
|
|
.INDENT 2.0
|
|
.IP \(bu 2
|
|
\fBmo_coef\fP
|
|
.IP \(bu 2
|
|
\fBread_wf\fP
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.SH AUTHOR
|
|
A. Scemama, E. Giner
|
|
.SH COPYRIGHT
|
|
2019, A. Scemama, E. Giner
|
|
.\" Generated by docutils manpage writer.
|
|
.
|