Dear A.Postnikov, Many thanks for your suggestions on our problem.Firstly We have calculated the lattice constant as 6.47 A (very cose to experiment , 6.48 A)for ground state bulk properties.But we have set the input file more before as you stated MD.TargetPressure 0.5 GPa MD.VariableCell T to obtain the new equilibrium lattice constant for future work (Cij vs P ).Our obtained lattice constants vs enegy values are not expected ones as follows :
lattice constant Energy 6.0 -1454,395571 6.1 -1454,390932 6.2 -1454,397768 6.3 -1454,397499 6.4 -1454,398580 6.5 -1454,395873 6.6 - 1454,397538 6.7 -1454,398341 6.8 -1454,382220 6.9 -1454,385354 As it can be seen , the data dont show the expected parabolic curve.So ,we can not obtain new correct- lattice constant .What is the reason of this discrepancy ? Your hint will appreciated Regards, Kemal Colakoglu, Gazi University, Dept.of Phys. ----- Original Message ----- From: "Andrei Postnikov" <[EMAIL PROTECTED]> To: <SIESTA-L@LISTSERV.UAM.ES> Sent: Tuesday, May 10, 2005 2:13 PM Subject: Re: [SIESTA-L] variation of lattice constants
On Tue, 10 May 2005, [iso-8859-9] Prof.Dr. Kemal ÇOLAKO^^LU wrote: | Dear Siesta users and developers, | We would like to see the pressure -dependence of elastic constansts on some semiconductors.But for this, firstly we need to calculate the pressure -dependence of lattice constants using Siesta.How can we enter the pressure to see the effect on energy ? Dear Kemal, you need to set MD.TargetPressure in combination with MD.VariableCell T Good luck, Andrei Postnikov +-- Dr. habil. Andrei Postnikov ----- Tel. +49-541-969.2377 -- Fax .2351 ---+ | Institut fuer Festkoerperforschung - FZ Juelich, D-52425 Juelich, Germany | +-- [EMAIL PROTECTED] --------- http://www.home.uni-osnabrueck.de/apostnik/ --+