= void DirectInterActEx1(REAL *pH00, REAL*pS00,REAL*pH01,REAL* pS01, REAL* Sbasis, REAL* aoI1e, REAL* aoI2e, REAL***pppC, INTEGER *nOcc, INTEGER *nBas, INTEGER *nOrb,REAL* pCorr2C) =
Now only support C(1) symmetry.

Types are defined [[Develop/Typedef|here]].
{{{
HEADER: source/noxci/DAct.h
}}}
{{{
LIB: libnoxci.a
}}}
{{{
SOURCE source/noxci/DAct.cpp
}}}
== REAL* Sbasis ==
Input, array size nBas*nBas, AO overlap matrix in Rectangle Full Packed format.
== REAL* aoI1e ==
Input, array size <<latex($\frac{nBas*(nBas+1)}{2}$)>>  , 1e AO integral symmetry matrix in lower triangle packed format.
== REAL* aoI2e ==
Input, array size <<latex($\frac{\frac{nBas*(nBas+1)}{2}(\frac{nBas*(nBas+1)}{2}+1)}{2}$)>>  , 2e AO integral symmetry 4D-matrix in lower triangle-liked packed format.
== REAL***pppC ==
Input, pppC[4][nEle][nBas], occupied MO coefficient. pppC[0]:A Alpha,nele=nOcc[0],pppC[1]:A Beta,nele=nOcc[1],pppC[0]:B Alpha,nele=nOrb[0],pppC[1]:B Beta,nele=nOrb[1]
== INTEGER *nOcc ==
Input, array size 2, alpha/beta occupation numbers
== INTEGER *nOrb==
Input, array size 2, number of alpha/beta orbitals
== INTEGER *nBas ==
Input, pointer to number of basis
== REAL* pCorr2C ==
Input, coefficient of double excitation. Order :<<BR>>
<<latex($\alpha\alpha\to\alpha\alpha$)>>(lower triangle packed format of occ orb & vir orb separately ),
<<latex($\beta\beta\to\beta\beta$)>>(lower triangle packed format of occ orb & vir orb separately ),
<<latex($\alpha\alpha\to\beta\beta$)>>(Rectangle Full Packed format).
== REAL *pH00 ==
Output, Save <<latex($\langle A_0\vert H\vert B_0\rangle$)>>  to the address the pointer points.
== REAL *pS00 ==
Output, Save <<latex($\langle A_0\vert S\vert B_0\rangle$)>>  to the address the pointer points.
== REAL *pH00 ==
Output, Save <<latex($\sum\langle A_0\vert H\vert B_1\rangle$)>>  to the address the pointer points.
== REAL *pS00 ==
Output, Save <<latex($\sum\langle A_0\vert S\vert B_1\rangle$)>>  to the address the pointer points.