From owner-chemistry@ccl.net Fri Dec 2 20:13:01 2011 From: "Jun Zhang coolrainbow * yahoo.cn" To: CCL Subject: CCL: How to calculate the independent degrees of freedom of a molecule? Message-Id: <-45972-111202201132-2659-lky+hEg5/08k3IUVy/1BDw[a]server.ccl.net> X-Original-From: Jun Zhang Content-Type: multipart/alternative; boundary="-849746693-977869748-1322874681=:77500" Date: Sat, 3 Dec 2011 09:11:21 +0800 (CST) MIME-Version: 1.0 Sent to CCL by: Jun Zhang [coolrainbow%a%yahoo.cn] ---849746693-977869748-1322874681=:77500 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello everyone:=0A=A0=0AFor a nonlinear N-atom molecule there are 3N-6 inte= rnal degrees of freedom, of course.=A0 However, for a point group-constrain= t molecule, such as C2v H2O, there are only 2 independent degrees of freedo= m. So, is=A0there a systematic way to determine the number and the contents= of independent degrees of freedom of an arbitarily symmetry-constraint mol= ecule? I heard that some knowledge like Polya theorem are requied, but I am= not sure. It will be better if some reviews can be reccommended.=0A=A0=0AT= hank you in advance. Any suggestions will be appreciated.=0A=A0=0ABest rega= rds!=0A=A0=0A--------------------------------------------------------------= --=0AJun Zhang (coolrainbow=-=yahoo.cn)=0AComputational Chemistry Group=0ANo.= 94, Weijinlu=0ANankai University =0ATianjin, China ---849746693-977869748-1322874681=:77500 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable

Hello ever= yone:

For a nonlinear = N-atom molecule there are 3N-6 internal degrees of freedom, of course. = ; However, for a point group-constraint mol= ecule, such as C2v H2O, there are only 2 independent degrees o= f freedom. So, is there a systematic way to determine the number and t= he contents of independent degrees of freedom of an arbitarily symmetry-con= straint molecule? I heard that some knowledge like Polya theorem are requie= d, but I am not sure. It will be better if some reviews can be reccommended= .

Thank you in advance= . Any suggestions will be appreciated.

Best regards!

------------------= ----------------------------------------------
Jun Zhang (coolrainbow=-=ya= hoo.cn)
Computational Chemistry Group
No.94, Weijinlu
Nankai Unive= rsity
Tianjin, China

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