= Traint =
<<TableOfContents(4)>>

{{{
Traint is used to transform AO-basis integrals to the MO basis for non-integral-direct post-HF and TDDFT.
}}}

== General keywords ==
=== FROZ ===
{{{#!wiki
The numbers of frozen core orbitals in $nreps irreps. 1 ≤ $nreps ≤ 8 since only Abelian group symmetry is supported.
}}}

=== DELE ===
{{{#!wiki
The numbers of virtual orbitals to be deleted in $nreps irreps. 1 ≤ $nreps ≤ 8 since only Abelian group symmetry is supported.
When expandmo set VSDS the output file has printed nsxvr as dele orbital numbers. 
}}}

=== ORBI ===
{{{#!wiki
For CISD and other single reference method, input HFORB; For MRPT2, MRCI and other multi-reference method, input MCORB
}}}
Example:
{{{
Orbital
mcorb
}}}

=== ORBTXT ===
{{{#!wiki
set to read BDF_WorkDir text orbital file, such as $BDF_WORKDIR/$BDFTASK.inporb 
}}}
Example:
{{{
Orbtxt
inporb
}}}

=== XvrUse ===
{{{#!wiki
The keyword for alternatively deleting virtual MOs by MCSCF XVR when keyword 'Dele' are not used to set delete MOs. Default is .false. However, the keyword 'Dele' is prior to 'XvrUse'.
}}}

=== MRPT2 ===
{{{#!wiki
The keyword for MO transformation to J (ij|rs) and K (ir|js) operators, otherwise for full MO transformation. This keyword is used for NEVPT2, MR-NEVPT2 and SDSPT2.
}}}

=== C4ITD ===
{{{#!wiki
The keyword for full MO transformation to the old MRCISD code of $DRT and $MRCI, otherwise no this keyword for the default full MO transformation using the J operator like code. This keyword can not calculate MO >255 for the molecule without symmetry.
}}}



Example:
{{{
mrpt2
}}}

=== REORDER ===
{{{#!wiki
N.A.
}}}

=== VAL ===
{{{#!wiki
N.A.
}}}

=== INTCRE ===
{{{#!wiki
  This keyword can change memory for AOINT saving. maxint=int(maxint*intcre). Default maxint is 268435456.
}}}


== For MCCEPA ==
=== MCCEPA ===
{{{#!wiki
N.A.
}}}

=== UNDMOL ===
{{{#!wiki
N.A.
}}}

== For TDDFT ==
=== UTDDFT ===
{{{#!wiki
Synonym: UMP2

Prepares the MO integrals for U-TDDFT and U-MP2 calculations.
}}}

=== TDDFT ===
{{{#!wiki
Synonyms: RTDDFT, MP2, RMP2

Prepares the MO integrals for R-TDDFT and R-MP2 calculations.
}}}

=== ALPHA ===
{{{#!wiki
The numbers of occupied alpha orbitals in $nreps irreps in the TDDFT calculation. 1 ≤ $nreps ≤ 8 since only Abelian group symmetry is supported.
}}}

=== BETA ===
{{{#!wiki
c.f. '''ALPHA'''.
}}}

=== OCCUP ===
{{{#!wiki
c.f. '''ALPHA'''.
}}}

== For FCI ==
=== FCIDUMP ===
{{{#!wiki
N.A.
}}}

=== SYMM ===
{{{#!wiki
N.A.
}}}

=== NELE ===
{{{#!wiki
N.A.
}}}

=== SPIN ===
{{{#!wiki
N.A.
}}}