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:
C. Moller and M. S. Plesset, "Note on an Approximation Treatment for
Many-Electron Systems," Phys. Rev. 46, 618 (1934).
Open-Shell Perturbation Theory
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).
M. Frisch, M. Head-Gordon, and J. Pople, "A Direct MP2 Gradient Method,"
Chem. Phys. Lett. 166, 275 (1990).
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:
Specifies the type of wave function desired. The only valid entry
at the present is MP2. There is no default.
Specifies the type of orbitals used for the single-determinant
reference function. Valid entries include RHF, UHF, and ROHF.
There is no default.
Determines the verbosity of the output. A value of 0 (the default)
specifies minimal printing.
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.
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.
If TRUE calculate the one-particle density matrix and
make OPDM_WRITE default to TRUE. The default value
of OPDM is FALSE.
Flag for whether or not to write the one-particle density matrix
Flag for whether or not to print the one-particle density matrix.