MOLPRO

17 THE DENSITY FUNCTIONAL PROGRAM 109
TOLORB=value
MATRIX=matrix
Threshold for orbital screening (current default 1.d-15).
Option to select integrator. matrix=0: use old (slow) integrator;
matrix=1: Use new matrix-driven integrator (default).
In addition, all options valid for HF (see section 16.1) can be given.
17.2 Directives
The following options may be used to control the operation of the DFT modules. In the Kohn-
Sham case, these may come in any order before or after directives for the SCF program as
described in Section 16.
17.2.1 Density source (DENSITY, ODENSITY)
DENSITY,orbc.filec,... ODENSITY,orbo.fileo,...
For non-self-consistent DFT calculations, specifies the source of the density matrix. The total
density is read from orbc.filec, with further options specifying density sets in the standard way
as described in Section 4.11. ODENSITY can be used to specify the spin density. The defaults
are the densities last written by an SCF or MCSCF program.
17.2.2 Thresholds (DFTTHRESH)
DFTTHRESH,key1=value1,key2=value2...
Sets various truncation thresholds. key can be one of the following.
TOTAL
ORBITAL
DENSITY
FOCK
Overall target accuracy (per atom) of density functional. Defaults
to the value of the global threshold GRID or the value
specified by option GRID. For proper use of this threshold,
other thresholds should be left at their default value of zero.
Orbital truncation threshold.
Density truncation threshold.
Fock matrix truncation threshold.
17.2.3 Exact exchange computation (EXCHANGE)
EXCHANGE,factor
For Kohn-Sham calculations, compute exchange energy according to Hartree-Fock formalism
and add the contribution scaled by factor to the fock matrix and the energy functional. Otherwise,
the default is factor=0, i.e., the exchange is assumed to be contained in the functional, and
only the Coulomb interaction is calculated explicitly.
DFTFACTOR,fac1, fac2, ...
Provide a factor for each functional specified. The functionals will be combined accordingly.
By default, all factors are one.