mp2 - Moller-Plesset Perburbation Theory
The module determines the second-order Moller-Plesset energy and
one-particle density matrix (OPDM) for RHF, UHF, and ROHF (using
semicanonical orbitals) references. Frozen orbitals can be used when
computing the energy but not the OPDM.
Original Moller-Plesset paper:
- 1.
- C. Moller and M. S. Plesset, "Note on an Approximation Treatment for
Many-Electron Systems," Phys. Rev. 46, 618 (1934).
Open-Shell Perturbation Theory
- 1.
- T. D. Crawford, H. F. Schaefer, and T. J. Lee, "On the energy
invariance of open-shell perturbation theory with respect to unitary
transformations of molecular orbitals," J. Chem. Phys. 105, 1060
(1996).
MP(2) Gradient Theory:
- 1.
- M. Frisch, M. Head-Gordon, and J. Pople, "A Direct MP2 Gradient
Method," Chem. Phys. Lett. 166, 275 (1990).
- 2.
- I. Nielsen, "A new direct MP2 gradient algorithm with implementation
on a massively parallel computer," Chem. Phys. Lett. 255, 210 (1996).
Input for this program is read from the file input.dat. The
following keywords are valid:
- WFN =
string
- Specifies the type of wave function desired. The only valid entry at the
present is MP2. There is no default.
- REFERENCE =
string
- Specifies the type of orbitals used for the single-determinant reference
function. Valid entries include RHF, UHF, and ROHF. There is no default.
- PRINT =
integer
- Determines the verbosity of the output. A value of 0 (the default)
specifies minimal printing.
- CACHETYPE=
string
- Selects the priority type for maintaining the automatic memory cache used
by the DPD codes. (See libdpd.html for further details.) A value of
LOW (the default) selects a "low priority" scheme in
which the deletion of items from the cache is based on pre-programmed
priorities. A value of LRU selects a "least recently
used" scheme in which the oldest item in the cache will be the first
one deleted.
- CACHELEV=
integer
- Selects the level of automatic cacheing desired in the storage of various
amplitudes, integrals, and intermediates in the coupled cluster procedure.
A value of 0 retains no quantities in cache, while a level of 6 attempts
to store all quantities in cache. For particularly large calculations, a
value of 0 may help with certain types of memory problems. The default is
2, which means that all four-index quantites with up to two
virtual-orbital indices (e.g., <ij|ab> integrals) may be held in the
cache.
- OPDM =
boolean
- If TRUE calculate the one-particle density matrix and make
OPDM_WRITE default to TRUE. The default value of OPDM
is FALSE.
- OPDM_WRITE
= boolean
- Flag for whether or not to write the one-particle density matrix to disk.
- OPDM_PRINT
= boolean
- Flag for whether or not to print the one-particle density matrix.