mirror of
https://github.com/QuantumPackage/qp2.git
synced 2024-11-14 10:03:47 +01:00
117 lines
2.8 KiB
Groff
117 lines
2.8 KiB
Groff
.\" Man page generated from reStructuredText.
|
|
.
|
|
.TH "NATURAL_ORBITALS" "1" "Mar 07, 2019" "2.0" "Quantum Package"
|
|
.SH NAME
|
|
natural_orbitals \- | 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
|
|
..
|
|
.SH SUMMARY
|
|
.sp
|
|
To produce state\-average natural orbitals, run
|
|
.INDENT 0.0
|
|
.INDENT 3.5
|
|
.sp
|
|
.nf
|
|
.ft C
|
|
qp_run save_natorb file.ezfio
|
|
.ft P
|
|
.fi
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.sp
|
|
The MOs will be replaced, so the two\-electron integrals and the wave
|
|
function are invalidated as well.
|
|
.SH EXTRACTING NATURAL ORBITALS
|
|
.sp
|
|
Once obtained the near FCI wave function, one can obtain many
|
|
quantities related to it. One of these quantities are the natural
|
|
orbitals which have the property of diagonalizing the one\-body
|
|
density matrix:
|
|
.INDENT 0.0
|
|
.INDENT 3.5
|
|
.sp
|
|
.ce
|
|
\erho_{ij} = \edelta_{ij}
|
|
.ce 0
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.sp
|
|
where the element of the one\-body density matrix \erho_{ij} is
|
|
defined as:
|
|
.INDENT 0.0
|
|
.INDENT 3.5
|
|
.sp
|
|
.ce
|
|
\erho_{ij} = \elangle \ePsi | \eleft( a^{\edagger}_{j,\ealpha} a_{i,\ealpha} + a^{\edagger}_{j,\ebeta} a_{i,\ebeta} \eright) |\ \ePsi\ \erangle
|
|
.ce 0
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.sp
|
|
These orbitals are in general known to be better than the usual HF
|
|
MOs as they are obtained from a correlated wave function. To use these
|
|
orbitals for future calculations, one has to replace the current MOs
|
|
by the natural orbitals. To do so, just run:
|
|
.INDENT 0.0
|
|
.INDENT 3.5
|
|
.sp
|
|
.nf
|
|
.ft C
|
|
qp_run save_natorb file.ezfio
|
|
.ft P
|
|
.fi
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.SH HANDS ON
|
|
.sp
|
|
\fBIMPORTANT:\fP
|
|
.INDENT 0.0
|
|
.INDENT 3.5
|
|
As the MOs are changed, for the sake of coherence of future
|
|
calculations, the save_natorb program \fIautomatically removes the
|
|
current wave function\fP stored in the \fI\%EZFIO\fP database and replaces
|
|
it by a single Slater determinant corresponding to a HF occupation
|
|
of the new spin orbitals. Also, all the keywords to read the one\-
|
|
and two\-electron integrals on the MO basis are set to \fBNone\fP in
|
|
order to be sure to avoid reading integrals incompatible with the
|
|
current set of MOs\&.
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.sp
|
|
\fBSEE ALSO:\fP
|
|
.INDENT 0.0
|
|
.INDENT 3.5
|
|
The documentation of the save_natorb program.
|
|
.UNINDENT
|
|
.UNINDENT
|
|
.SH AUTHOR
|
|
A. Scemama, E. Giner
|
|
.SH COPYRIGHT
|
|
2019, A. Scemama, E. Giner
|
|
.\" Generated by docutils manpage writer.
|
|
.
|