I must also add two things here: when I adjust the coordinate in such a way that angle 2-1-3 becomes 0.0, this consequents in angle 1-2-3 becoming 179.999... <br><br>Secondly if I just give the three carbon atoms without the hydrogen atoms, the angles are nevertheless the same but the program approximates it to the abelian C2v group.<br>
<br><br><div class="gmail_quote">On Tue, Dec 21, 2010 at 5:07 PM, raman v <span dir="ltr"><<a href="mailto:vraman16@gmail.com">vraman16@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Many thanks for the prompt response from Peter and Sham. I did change
the Z coordinate of the last hydrogen and resubmitted using the same
input that I had mailed last time. It was indeed identified as C2v. so
using this corrected coordinate when I submitted the EOM job, once again
it identified it as Cs. I have appended herewith the relevant
portion of the output file of the EOM job where you can see the input
coordinate as well as the point group identification by the program.<br><br>=========================================================================<br><br> Geometry written to block 1 of record 700<br><br><br> Point group Cs<br>
<br><br><br> ATOMIC COORDINATES<br><br> NR ATOM CHARGE X Y Z<br><br> 1 C 6.00 0.000000000 0.000000000 0.277171401<br> 2 C 6.00 0.000000000 0.000000000 1.025368410<br>
3 C 6.00 0.000000000 0.000000000 2.367681277<br> 4 H 1.00 0.000000000 -0.924341858 2.942060857<br> 5 H 1.00 0.000000000 0.924341858 2.942060857<br><br> CAUTION<br> VERY SHORT BOND LENGTHS PRESENT - IS THIS RIGHT?<br>
<br><br> Bond lengths in Bohr (Angstrom)<br><br> 1-2 0.748197009 1-3 2.090509876 1-4 2.820645969 1-5 2.820645969 2-3 1.342312867<br> (0.395928805) (1.106250182) (1.492621562) (1.492621562) (0.710321377)<br>
<br> 2-4 2.127937454 2-5 2.127937454 3-4 1.088264569 3-5 1.088264569<br> (1.126056003) (1.126056003) <span style="background-color: rgb(255, 255, 0);">(0.575884807) (0.575884807)</span><br><br> Bond angles<br>
<br> <span style="background-color: rgb(255, 255, 51);">1-2-3 180.00000000</span> 1-2-4 154.25390041 1-2-5 154.25390041 1-3-2 0.00000000<br><br> 1-3-4 121.85652945 1-3-5 121.85652945 1-4-2 6.61651767 1-4-3 39.01388864<br>
<span><span style="background-color: rgb(255, 255, 0);"></span></span><br> 1-5-2 6.61651767 1-5-3 39.01388864 <span style="background-color: rgb(255, 255, 0);"> <span style="background-color: rgb(255, 0, 0);">2-1-3 0.00000085 </span></span> 2-1-4 19.12958192<br>
<br> 2-1-5 19.12958192 <span style="background-color: rgb(255, 255, 0);">2-3-4 121.85652945 2-3-5 121.85652945</span> 2-4-3 32.39737096<br><br> 2-5-3 32.39737096 3-1-4 19.12958192 3-1-5 19.12958192 3-2-4 25.74609959<br>
<br> 3-2-5 25.74609959 4-1-5 38.25916383 4-2-5 51.49219918 4-3-5 116.28694111<br><br>=================================================================================<br><br>You may please see that angle 1-2-3 is 180.00 whereas angle 2-1-3 is
0.00000085. The other angles and bond lengths that I have highlighted in yellow are
in fact perfect and thus, due to this angle 2-1-3 alone that the
program is identifying it as Cs.<br><br>Regards<br><font color="#888888">raman<br>
<span><span style="background-color: rgb(255, 255, 0);"></span></span><br><br>
</font></blockquote></div><br><br clear="all"><br>-- <br>Regards,<br>V. Ramanathan.<br><br>"To grow old is mandatory, to mature is optional."<br><br>"Knowledge is like food. We can share it only if we have it."<br>
<br><br>