Verified Commit f88ff261 authored by Jellby's avatar Jellby

doc: CRPR and updated BINA keywords

Documentation updates from Per Åke
parent 991a1f40
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......@@ -3509,7 +3509,7 @@
Doi = {10.2533/chimia.2016.244}
}
@article{Granovsky2011,
@Article{Granovsky2011,
Title = {Extended multi-configuration quasi-degenerate perturbation theory: The new approach to multi-state multi-reference perturbation theory},
Author = {A. A. Granovsky},
Journal = jcp,
......@@ -3519,7 +3519,7 @@
Doi = {10.1063/1.3596699}
}
@article{Shiozaki2011,
@Article{Shiozaki2011,
Title = {Communication: Extended multi-state complete active space second-order perturbation theory: Energy and nuclear gradients},
Author = {T. Shiozaki and W. Gy{\H{o}}rffy and P. Celani and H.-J. Werner},
Journal = jcp,
......@@ -3528,3 +3528,14 @@
Year = {2011},
Doi = {10.1063/1.3633329}
}
@Article{Malmqvist:2012,
Title = {The binatural orbitals of electronic transitions},
Author = {Malmqvist, Per {\AA}ke and Veryazov, Valera},
Journal = mp,
Pages = {2455--2464},
Volume = {110},
Year = {2012},
Number = {19-20},
Doi = {10.1080/00268976.2012.697587}
}
......@@ -217,6 +217,41 @@ The program will do this automatically with the use of the
input keyword :kword:`LINEAR`. Similarly, for single atoms, spherical
symmetry can be enforced by the keyword :kword:`ATOM`.
.. _UG\:sec\:core-hole:
States with a core hole
-----------------------
.. compound::
For stable calculation of states with a deep hole, e.g. for X-ray transitions, one needs to compute
a (number of) states with a core hole, and a (number of) states without the core hole, with quite
different orbitals, and then presumably combine these states in a RASSI calculation. The core-hole
state(s) cannot be computed in the same calculation as the full-core states, since they will be very highly excited states
compared to the states without that hole. There is also the problem of preventing orbital optimization
from filling the core hole. In order to make the calculation in a way that is stable, also across
calculations with changing geometry, there is a special input to :program:`RASSCF`.
The option :kword:`CRPR` stands for "core projection", and is followed by two numbers, e.g. as ::
CRPR
1 33.0
which has the effect of selecting one orbital, in this case orbital nr. 1, from the starting orbitals.
This orbital should be in symmetry 1, a non-degenerate orbital, doubly occupied in the state without
core hole. A projection operator is constructed from the AO basis set, and in the subsequent
CI calculations, in each new iteration of the orbital optimizer, this operator is multiplied with
a shift, in this case 33.0 a.u., and added to the Hamiltonian. Regardless of the changing
orbitals, this operator is defined by the stable AO basis, and any configuration where the core
orbital is doubly occupied is shifted upwards in energy, above the core hole states, and are
prevented from playing any role in the calculation. The converged solution(s) are used in a
subsequent RASSI, for instance (then with the unperturbed Hamiltonian, of course), where it is
combined with states without core hole, for energies and transition properties.
The perturbation on the core hole states by the projection shift is small, provided that the
basis set is able to to include the core relaxation effect, and the subsequent RASSI is
helpful in correcting for any effects of the perturbation since it will anyway compute
eigenstates which are non-interacting and orthogonal by state mixing.
.. _UG\:sec\:StochasticCAS:
Stochastic-CASSCF method
......@@ -899,6 +934,26 @@ A list of these keywords is given below:
</HELP>
</KEYWORD>
:kword:`CRPRoject`
This keyword is followed by two numbers, which define a Hamiltonian shift by a
projection operator times a scalar number. For choosing these numbers, please
read the section about core hole states above.
The shift acts to raise the energy of any configuration where the selected
orbital is doubly occupied so the lie far enough above the target core hole
states for the duration of the calculation. The purpose is to obtain RASSCF
states that are properly optimized, yet with no risk of collapsing the core
hole, for use in subsequent RASSI calculations.
.. xmldoc:: <KEYWORD MODULE="RASSCF" NAME="CRPR" LEVEL="ADVANCED" APPEAR="Core project" KIND="STRING">
%%Keyword: CRPRoject <advanced>
<HELP>
This keyword is followed by two numbers, which define a Hamiltonian shift by a
projection operator times a scalar number. For choosing these numbers (integer
and real), please read the section about core hole states in the manual for
the RASSCF program.
</HELP>
</KEYWORD>
:kword:`ATOM`
This keyword is used to get orbitals with pure spherical
symmetry for atomic calculations (the radial dependence can vary for different
......
......@@ -24,8 +24,8 @@
computed also for the non-interacting linear combinations of states,
i.e., doing a limited CI using the RASSCF states as a non-orthogonal basis.
RASSI is extensively used for computing dipole oscillator strengths.
Finally, it can also compute Spin-Orbit interaction matrix elements
and e.g. transition dipole moments for spin-orbit eigenstates.
Finally, it can also compute e.g. spin-orbit interaction matrix elements,
transition dipole moments, (bi-)natural orbitals and other quantities.
</HELP>
The
......@@ -276,9 +276,11 @@ Output files
A number of files containing natural orbitals, (numbered sequentially as
:file:`SIORB01`, :file:`SIORB02`, etc.)
:file:`BRAORBnnmm`, :file:`KETORBnnmm`
:file:`BIORBnnmm`
A number of files containing binatural orbitals for the transition between
states nn and mm.
states ``nn`` and ``mm``. Each such file contains pairs of orbitals, in the same format
as the :math:`\alpha` and :math:`\beta` components of UHF orbitals. The file for transition
to state ``nn``\ =2 from state ``mm``\ =1 will be named :file:`BIORB.2_1`.
:file:`TOFILE`
This output is only created if :kword:`TOFIle` is given in the input.
......@@ -509,13 +511,13 @@ Keywords
:kword:`SOPRoperty`
Enter a user-supplied selection of one-electron operators, for which
matrix elements and expectation values are to be calculated over the
of spin--orbital eigenstates. This keyword has no effect unless the
spin--orbit eigenstates. This keyword has no effect unless the
:kword:`SPIN` keyword has been used. Format: see :kword:`PROP` keyword.
.. xmldoc:: %%Keyword: SOProperty <basic>
Enter a selection of one-electron operators, for which
matrix elements and expectation values are to be calculated over the
of spin-orbital eigenstates. This keyword has no effect unless the
spin-orbit eigenstates. This keyword has no effect unless the
SPIN keyword has been used. Format: see PROP keyword.
:kword:`SPINorbit`
......@@ -697,18 +699,18 @@ Keywords
:kword:`BINAtorb`
The next entry gives the number of transitions for which binatural
orbitals will be computed. Then a line should follow for each transition,
with the two states involved. The binatural orbitals will be written, formatted, commented,
and followed by singular values, on two files for each transition.
For file names, see the Files section.
The format allows their use as standard orbital input files to
other |molcas| programs.
with the two states involved. The orbitals and singular values provide a
singular value decomposition of a transition density matrix \cite{Malmqvist:2012}.
The bra and ket orbitals are written followed by the singular values in the
usual UHF format used by other |molcas| programs.
.. xmldoc:: <KEYWORD MODULE="RASSI" NAME="BINATORB" APPEAR="Binatural Orbitals" KIND="INTS_COMPUTED" SIZE="2" LEVEL="BASIC">
%%Keyword: BiNatOrb <basic>
<HELP>
Enter the number of eigenstates, for which binatural orbitals should
be computed and written to file. These will be written together with
the singular values in the usual format used by MOLCAS.
Enter the number of transitions, for which binatural orbitals should
be computed and written to file. Then a line should follow with the two
states for each transition. The ket and the bra orbitals are written
followed by the singular values in the the usual format used by MOLCAS.
</HELP>
</KEYWORD>
......
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