As far as i know, the best tool to determine symmetry of any object is out brain. I would suggest you to read some text book about symmetry in chemistry: https://www.google.com/search?client=ubuntu&channel=fs&q=symmetry+in+chemisrty&ie=utf-8&oe=utf-8#q=symmetry+in+chemistry+book&hl=en&client=ubuntu&hs=qne&tbo=u&channel=fs&source=univ&tbm=shop&sa=X&ei=4kbPULSIIaX72QW4_YCYBQ&ved=0CEsQsxg&bav=on.2,or.r_gc.r_pw.r_qf.&b
I don't want to discuss which text-book is better. For beginners i would recommend this https://www.google.com/shopping/product/9653951631802363966?hl=en&gs_nf=3&gs_rn=1&gs_ri=serp&tok=n-13gEGu7IgP7QXPyON28Q&ds=sh&pq=symmetry+in+chemistry+book&cp=19&gs_id=2n2&xhr=t&q=carter%20group%20theory&pf=p&client=ubuntu&hs=zoe&channel=fs&sclient=psy-ab&oq=carter+group+theory&gs_l=&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&bvm=bv.1355325884,d.b2I&bpcl=39967673&biw=1317&bih=650&sa=X&ei=K0fPUPmTLvGk2gWr64H4BQ&sqi=2&ved=0CFcQ8wIwAQ
Cheap and efficient. Of course there are a lot of information in WWW. Fill free to use. Some program (wxmacmolplt, gabedit) can fit geometry of your molecule to have appropriate point group, but the geometry should be already as close as possible to those symmetries.
On Mon Dec 17 '12 2:05pm, Siddheshwar Chopra wrote
>Is there any way I can know the symmetry of a molecule/ cluster/ thin film (graphene)? Or is there a software available to do that? The reason why I am asking this question is that I am using C1 (o symmetry) and it takes too long for samples with more no. of atoms. Please help. Could you suggest me some online material if needed?