I did not read the paper, but O(delta^3) term should be the omitted term in series expansion, and it looks like Const delta^3. To recover the value of the constant, one should repeat the derivation of equation and keep the next order term.
Valentin. bipul rakshit wrote: > Respected Sushil Auluck, > Thanks for your kind reply. As you said that the term means of order delta cube. > But I just want to know the equation of that term. Means how that order delta cube, mathematically looks like. I asked this because, using that equation, I have to find the elastic constants. > regards > > Bipul Rakshit > PhD in Physics > Computational Research Lab. > Barkatullah University, > Bhopal 462 026, India > Mob.: +919713445650 > > --- On Mon, 13/7/09, Sushil Auluck <saul...@iitk.ac.in> wrote: > > > From: Sushil Auluck <saul...@iitk.ac.in> > Subject: Re: [SIESTA-L] question about elastic constant > To: SIESTA-L@listserv.uam.es > Date: Monday, 13 July, 2009, 9:48 PM > > hi, > that means terms of order delta cubed (delta**3)...... > s.auluck > > > Dear Siesta Users, > > I have read the paper > > "S. Q. Wang, H. Q. Ye, J. Phys.: Condens. Matter 15 (2003) p. 5307." > > > > Most of the thing is clear to me, except in Equation (7) what is "O(^3)" > > ? What does 'O' here. > > > > > > Please guide me for the same. > > > > > > Bipul Rakshit > > > > PhD in Physics > > > > Computational Research Lab. > > > > Barkatullah University, > > > > Bhopal 462 026, India > > > > Mob.: +919713445650 > > > > > > See the Web's breaking stories, chosen by people like you. Check > > out Yahoo! Buzz. http://in.buzz.yahoo.com/ > > > ........................................................................ > Prof. Sushil Auluck Phone:+91-512-6797092/6148 > Department of Physics +91-512-6798177(Home) > Indian Institute of Technology Cell :+91-9305548667 > Kanpur 208016 (UP) Fax :+91-512-6790914 > India E-mail:saul...@iitk.ac.in > ...............................................:saul...@gmail.com > http://www.iitk.ac.in/phy/People/phy_facvis.html > http://www.iitk.ac.in/phy/New01/profile_SA.html > ....................................................................... > ~ > > > See the Web's breaking stories, chosen by people like you. Check out Yahoo! Buzz. -- Valentin V. Karassev ______________________________________________ University of Florida Quantum Theory Project 2300 NPB #92 P.O. Box 118435 Gainesville, FL, 32611-8435 tel: (352)870-2453 fax: (352)392-8722 ______________________________________________ C. Quimica, IVIC tel/fax: 58(212)504-1356 web: http://www.ivic.ve/quimica/fqteorica/
