TransformationThis
keyword controls the algorithm used for integral transformation, as well as the
types of transformed integrals produced. INTEGRAL TRANSFORMATION ALGORITHM
OPTIONSDirect Requests that the direct transformation routines
be used. Equivalent to L804. Link 804 will select between the in-core,
fully direct, and semi-direct methods automatically. This is the default. InCore
Forces use of the in-core algorithm in Link 804 FullDirect Forces
use of the fully direct (MO integrals in core) method in Link 804. SemiDirect
Forces use of the semi-direct algorithm in Link 804. Conventional
Requests that the original transformation method based on externally stored integrals
be used. This was the only choice in Gaussian 90 and earlier versions.
NoDirect is a synonym for Conventional. Old2PDM
Forces the old-fashioned process of the 2PDM in post-SCF gradients (sorted in
L1111 and then processed in L702 and L703). This is slow, but it reduces memory
requirements. This option cannot be used for frozen-core calculations. New2PDM
Causes the 2PDM to be generated, used, and discarded by L1111 in post-SCF gradient
calculations. This is the default and fastest method, and it must be used for
frozen-core calculations. INTEGRAL SELECTION OPTIONSFull
Forces a transformation over all orbitals (i.e., including transformed integrals
involving all virtuals). ABCD is a synonym for Full. IJAB
Produce only <IJ||AB> integrals. IAJB Produce <IJ||AB>
and <IA||JB> integrals. IJKL Produce <IJ||AB>, <IA||JB>,
and <IJ||KL> integrals. IJKA Produce <IJ||AB>, <IA||JB>,
<IJ||KL>, and <IJ||KA> integrals. IABC Produce <IJ||AB>,
<IA||JB>, <IJ||KL>, <IJ||KA>, and <IA||BC> integrals. |