Multi-reference CC active space setting for Sc2

Dear All

I would like to do the MRCCSDTQ calculation for Sc2 molecule, but I found that the multiplicity is changed by the MRCC program. It may be the problem of the wrong active space for multiplicity 5. I know how to set the singlet state calculation, but how do I set the right active space for multiplicity 5 ? I would like to consider all 4s and 3d orbitals for each Sc. The following is my input file and the information for change of multiplicity.

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My Input

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# CCSD(T) calculation for triplet CH2 with cc-pVTZ basis, UHF orbitals
basis=m6-31G*
calc=CCSDTQ
mem=8000MB
mult=5
scfmaxit=130
#active=serialno
#19,20,21,22,23
nacto=5
nactv=1
#gopt=full
#freq=on
#symm=off

geom=xyz
2

SC 0.000000000000 0.000000000000 0.000000000000
SC 2.750000000000 0.000000000000 0.000000000000

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The change of multiplicity in output

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Allocation of 643.4 Mbytes of memory...
Number of spinorbitals: 100
Number of alpha electrons: 5
Number of beta electrons: 1
Spin multiplicity: 2
z-component of spin: 2.0
Spatial symmetry: 5
Convergence criterion: 1.0E-06
Construction of occupation graphs...
Number of 0 -fold excitations: 1
Number of 1 -fold excitations: 44
Number of 2 -fold excitations: 2761
Number of 3 -fold excitations: 78600
Number of 4 -fold excitations: 962852

Thanks a lot

You should select the active space using the active keyword as
active=serialno
1-5

Thank for your suggestion, Dr. kallay. I understand how to set the active space now.