MOLPRO

11 BASIS INPUT 74
The specifications SET, DEFAULT, atom=name are all optional. If DEFAULT is not given, the
previous default, as specified on the last previous BASIS card, is used.
Several BASIS cards and/or blocks can immediately follow each other. Always the last specification
for a given atom and setname is used (the default setname is ORBITAL).
If a basis is not specified at all for any unique atom group, then the program assumes VDZ.
11.7 Auxiliary basis sets for density fitting or resolution of the identity
As described in the previous section, several basis sets can be defined in a basis block. The
definition of each basis starts with a line
SET,name,[CONTEXT=context]
where name is an arbitary name that can be used later to choose the basis set using options like
df basis=name, ri basis=name etc. CONTEXT can optionally be specified to select the
basis types JFIT, JKFIT, MP2FIT, CCSDFIT, or OPTRI. This affects the choice of default
basis sets. For example
basis={
default=avtz !default orbital basis set
set,df,context=mp2fit
default,avtz !use avtz/mp2fit
set,jk,context=jkfit
default,avtz !use avtz/jkfit
}
is equivalent to
basis={
default=avtz
set,df
default,avtz/mp2fit
set,jk
default,avtz/jkfit
}
!default orbital basis set
!use avtz/mp2fit
!use vtz/jkfit
If the setname begins with JFIT, JKFIT, MP2FIT, CCSDFIT, or OPTRI, these strings define
the default context.
Specific basis sets for individual atoms or explicit input of exponents and contraction coefficients
can be given exactly in the same way as for orbital basis sets.
11.8 Primitive set definition
Default basis sets given using one-line BASIS commands or DEFAULT directives in a basis
block can be overwritten by explicit specifications of basis functions (type, exponents, contraction
coefficients).
A group of basis functions is defined by a data card specifying a set of primitive gaussians,
optionally followed by one or more cards specifying particular contractions of primitives to be
included in the final basis (see section 11.9 for specification of contractions).