Gaussian 03 Online Manual
Last update: 2 October 2006

BD

This method keyword requests a Brueckner Doubles calculation [73,74].

T
Requests a Brueckner Doubles calculation with a triples contribution [73] added. BD-T is a synonym for BD(T).

TQ
Requests a Brueckner Doubles calculation with triples and quadruples contributions [64] added.

FC
This indicates "frozen-core," and it implies that inner-shells are excluded from the correlation calculation. This is the default calculation mode. See FC for full information.

MaxCyc=n
Specifies the maximum number of cycles.

Analytic energies, numerical gradients, and numerical frequencies.

The BD energy appears in the output labeled E(CORR), following the final correlation iteration:

DE(CORR)=   -.55299518D-01     E(CORR)=     -.75019628089D+02 

The energy is given in Hartrees. If triples (or triples and quadruples) were requested, the energy including these corrections appears after the above:

 
Brueckner Doubles with Triples and Quadruples (BD(TQ)) 
======================================================== 
Saving the triples amplitudes on disk, using 192 words of disk. 
T4(aaa)=  .00000000D+00 
T4(aab)= -.40349028D-04 
T4(abb)= -.40349028D-04 
T4(bbb)=  .00000000D+00 
Time for triples=       .10 seconds. 
Disk space used for TT scratch files :      512 words 
E5TTaaa =   .00000000D+00E5TTaab =   -.12350750D-04 
E5TTabb =  -.12350750D-04 
E5TTbbb =   .00000000D+00 
E5TT     =   -.24701500D-04 
E5TQ2    =    .68473650D-05 
EQQ2     =   -.44495423D-04 
DE5  =    -.62349557751D-04  BD(TQ)  =   -.75019771137D+02

The section gives information about the computation of the non-iterative triples and quadruples correction. The final energy appears in the last line, labeled BD(TQ).