Dear Mitul If I remember well you cannot perform NEB calculations in a variable-cell framework. You should choose a reasonable set of lattice parameters along the whole reaction path. HTH Giuseppe
On Thursday 06 February 2014 07:36:18 Mitul Mundra wrote: > Hello, > > I need to do NEB calculations for my system. My system consists of Si 2*2*2 > supercell with some Li impurities. Prior to NEB, I am doing a vc-relax > calculation to get the minimum energy states for the first and the last > images of the NEB. For the vc-relax, I set *ibrav = 1* for the symmetric > cubic system. In the results obtained from vc-relax calculation, the cubic > symmetry of the system is lost and I get the following call parameters for > the initial and final state in the output file. > > CELL_PARAMETERS (alat= 20.51108588) > 1.011059885 -0.002882944 -0.000008465 > -0.002882944 1.011059885 0.000008465 > -0.000008492 0.000008492 1.007297719 > > CELL_PARAMETERS (alat= 20.51108588) > 1.004932042 0.000000442 -0.000000442 > 0.000000442 1.004688370 0.000104290 > -0.000000442 0.000104290 1.004688370 > > Now, I am confused about my input file for the NEB. I can not just directly > change the lattice constant by taking the cube root of the new volume > obtained. I tried to set* ibrav = 0* and give the cell parameters obtained > but I can only enter them once (correct me if I am wrong) and thus, can not > incorporate both the set of cell parameters. I would be extremely thankful > if anyone could suggest me a way to tackle this difficulty. > > > Thanks > Mitul Mundra > Final year Dual Degree Student > Department of Chemical Engineering > IIT Kanpur ******************************************************** - Article premier - Les hommes naissent et demeurent libres et ?gaux en droits. Les distinctions sociales ne peuvent ?tre fond?es que sur l'utilit? commune - Article 2 - Le but de toute association politique est la conservation des droits naturels et imprescriptibles de l'homme. Ces droits sont la libert?, la propri?t?, la s?ret? et la r?sistance ? l'oppression. ******************************************************** Giuseppe Mattioli CNR - ISTITUTO DI STRUTTURA DELLA MATERIA v. Salaria Km 29,300 - C.P. 10 I 00015 - Monterotondo Stazione (RM) Tel + 39 06 90672836 - Fax +39 06 90672316 E-mail: <giuseppe.mattioli at ism.cnr.it> ResearcherID: F-6308-2012
