Mr. Deb,

Here: http://gaussian.com/field/

If your molecule is not so large you could show the coordinates.

Ms. Ivanova,

I am Sorry. I could not get your point. I have already seen the link you added. If you elaborate your point it would be helpful.

Hi Deb,

I am not an expert in electric field optimizations but I think you can do it "manually". You can display the cartesian axes in Gaussview and then align the specific bond along the axes (moving the molecule by Alt+shift to translate and Alt+Ctrl to rotate). It is not exact, but then you can modify the cartesian coordinates changing the values like 0.002893939 to 0.00000 to be sure that the specific atoms are aligned with the axed.

Hope it helps!

Ignacio

Thanks Funes . Your suggestion actually worked out. In addition, I would like to mention that after aligning a bond along a cartesian axis, one need to use that output and open in "Molden". In "Molden" the z matrix need to be reordered choosing one of the aotm of that bond as reference. The other atom of the bond should be kept in second position in z-matrix. Finally, the input for gaussian need to be given in z-matrix format.

An example of the input file is given bellow,

%chk=acetophenone_Nfield58.chk

# opt=z-matrix freq b3lyp/6-311++g(d,p) field=z-58 nosymm scf=tight

acetophenone_N58field

0 1

c

o 1 oc2

h 1 hc3 2 hco3

h 3 hh4 1 hhc4 2 dih4

h 4 hh5 3 hhh5 1 dih5

c 1 cc6 3 cch6 4 dih6

c 1 cc7 6 ccc7 4 dih7

h 7 hc8 1 hcc8 6 dih8

c 7 cc9 1 ccc9 6 dih9

h 9 hc10 7 hcc10 1 dih10

c 9 cc11 7 ccc11 1 dih11

h 11 hc12 9 hcc12 7 dih12

c 11 cc13 9 ccc13 7 dih13

h 13 hc14 11 hcc14 9 dih14

c 13 cc15 11 ccc15 9 dih15

h 7 hc16 9 hcc16 11 dih16

c 7 cc17 9 ccc17 11 dih17

oc2 1.221000

hc3 2.110310

hco3 90.923

hh4 1.758220

hhc4 66.653

dih4 -147.234

hh5 1.748789

hhh5 60.178

dih5 -75.669

cc6 1.503315

cch6 28.916

dih6 32.822

cc7 1.488945

ccc7 119.959

dih7 60.040

hc8 2.143429

hcc8 96.859

dih8 -0.027

cc9 1.391926

ccc9 122.292

dih9 -0.046

hc10 2.132196

hcc10 146.275

dih10 179.988

cc11 1.386846

ccc11 120.461

dih11 179.965

hc12 2.132655

hcc12 145.735

dih12 0.142

cc13 1.385775

ccc13 119.938

dih13 0.106

hc14 2.135866

hcc14 145.705

dih14 -0.047

cc15 1.388600

ccc15 120.007

dih15 -0.066

hc16 2.124435

hcc16 145.323

dih16 -0.139

cc17 1.393768

ccc17 119.109

dih17 -0.108