[molpro-user] Too many active orbitals in CASPT2 Calculation?

[Brian Vest]

I have been trying to run a CASPT2 calculation with a (12,14) active
space.  For debugging purposes, I simply limited the active space to
(4,4).  Here's the input file:

***,CrF2 Dimer
memory,300000000
gprint,basis,orbital=5,civector
geomtyp=xyz
geometry={
6
CrF2 Dimer
Cr,       -1.537948,    0.147900,    0.004020
F,      -0.000004  ,  1.417027  ,  0.005595
Cr,        1.537951,    0.147912,    0.004031
F,       0.000001  , -1.074047  ,  0.051993
F,      -3.193075  , -0.565898  , -0.039522
F,       3.193071  , -0.565912  , -0.039535
}
basis=LanL2DZ
uhf;wf,64,1,0,0;occ,32;closed,32
option,iptyp=diis,accura=13,ipnit=2,ipstep=1,maxdis=100,maxit=500
save,2200.2
multi;start,2200.2;occ,34;closed,30;maxiter,100;accuracy,energy=1.0D-08
!iprint,micro
rs2

The CASSCF converged nicely, but when the RS2 part of the program began,
I received this error:

1PROGRAM * RS2 (Multireference RS Perturbation Theory)     Authors:
H.-J. Werner (1993), P. Celani (1998)


 TOO MANY ACTIVE ORBITALS: 22 THIS VERSION ALLOWS 16

 ERROR EXIT
 CURRENT STACK:      CIINP  CIPRO  MAIN



**********************************************************************************************************************************
 DATASETS  * FILE   NREC   LENGTH (MB)   RECORD NAMES
              1      21       64.21       600      500      700      960
900      950      970     1000     1100     1400
                                        BASINP     VAR     GEOM
ABASIS   SYMINP    ZMAT    AOBASIS   BASIS      S        T
                                         1410     1420     1200     1210
1080     1600      129     1650     1300     1700
                                           V       ECP      H0       H01
AOSYM     SMH      P2S    MOLCAS    ERIS     OPER
                                         1380
                                         JKOP

              2       4        0.67       700     1000     2200     2140
                                         GEOM     BASIS     UHF
MCSCF

 PROGRAMS   *        TOTAL       RS2     MULTI   UHF-SCF       INT
 CPU TIMES  *       190.43      0.00    143.55     40.81      5.97
 REAL TIME  *       222.04 SEC
 DISK USED  *       331.12 MB

**********************************************************************************************************************************

 GA ERROR termxy

I thought there might be a problem with the a RS2 calculation with
pseudopotentials, so I reran the same calculation without the
pseudopotentials in the LanL2DZ basis set and received the same error.
Any ideas what's going on?