NAME
mp2r12 - calculates the MP2-R12 energy in standard approximation A for
closed-shell systems.
DESCRIPTION
The program mp2r12 determines the linear-R12 second-order Moller-Plesset energy
for closed-shell systems. Input integrals must come from the restricted
transformation available in the TRANSQT program. Frozen orbitals are not
allowed, as the basis sets used in linear-R12 computations employ basis sets
with more than enough flexibility to describe core-correlation effects
correctly.
REFERENCES
Moller-Plesset original paper:
1.
.nr )E 0
C. Moller and M. S. Plesset, "Note on an Approximation Treatment for
Many-Electron Systems", Phys. Rev., 46, 618(1934).
Linear R12 theory formulation:
2.
.nr )E 0
W. Kutzelnigg and W. Klopper, "Wave functions with terms linear in the
interelectronic coordinates to take care of the correlation cusp. I. General
Theory", J. Chem. Phys., 94, 1985(1991).
MP2-R12/A programmable expressions:
3.
.nr )E 0
W. Klopper, "Limiting values for Moller-Plesset second-order correlation
energies of polyatomic systems: A benchmark study on Ne, HF, H2O, N2, and
He...He", J. Chem. Phys., 102, 6168(1995).
input.dat
FILE30
FILE72 (electron repulsion integrals, produced by transqt)
FILE79 (integrals of r12 operator, produced by transqt)
FILE80 (integrals of [r12,T2] operator, produced by transqt)
output.dat
INPUT OPTIONS
mp2r12 has the following options:
PRINT_LVL =
integer
.nr )E 0
Determines the verbosity of the printing information. A print value of 0 gives
minimal information, while 5 gives debugging information (do NOT use print
levels above 3 for more than 20 basis functions). The default is 0.
TOLERANCE =
integer
.nr )E 0
This gives the exponent of the cutoff value for the elimination of two-electron
integrals from the list of those on disk. The default is 14, giving a cutoff
of 1e-14.
FROZEN_DOCC =
int_array
.nr )E 0
Number of frozen doubly-occupied orbitals in each symmetry block. Default is a
vector of zeroes.
FROZEN_UOCC =
int_array
.nr )E 0
Number of frozen unoccupied orbitals in each symmetry block. Default is a vector
of zeroes.
C_LIMIT =
boolean
.nr )E 0
Instead of using variationally optimized C-coefficients, use limiting values
(1/2 for singlet pairs, 1/4 for triplet pairs). Default is false.