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Mihai Medeleanu
mihai.medeleanu@upt.ro

I have the following problem: when I compute the dipole moment for protonated amines (for instance methylammonium cation) I obtain a value ten times greater than with GAMESS-US or other quantum chemistry program. For the mentioned compound Firefly (8.1.1) gave me 15.5157 Debye (which in any case is a too big value!). For non-protonated amines the results are OK (same results on both programs). I used DFT B3LYP 6-31G.
Data for methylammonium cation:

!   File created by the GAMESS Input Deck Generator Plugin for Avogadro
$BASIS GBASIS=N31 NGAUSS=6 NDFUNC=1 NPFUNC=1 $END
$CONTRL SCFTYP=ROHF RUNTYP=OPTIMIZE DFTTYP=B3LYP MULT=1 ICHARG=1 $END
$STATPT OPTTOL=0.0001 NSTEP=20 $END

$DATA
maH
C1
C     6.0    -4.04405     1.60919    -0.01255
N     7.0    -2.50801     1.70111     0.00782
H     1.0    -4.43069     0.72487    -0.54256
H     1.0    -4.44207     2.50496    -0.50704
H     1.0    -4.43860     1.59341     1.01009
H     1.0    -2.05318     1.66836    -0.91632
H     1.0    -2.04559     0.90265     0.50765
H     1.0    -2.14817     2.57106     0.42741
$END