[Pw_forum] fix lattice constant

[Paolo Giannozzi]

On Monday 06 February 2006 07:26, y wang wrote:

>   I want to calculate the strained PbTiO3. How to perform a relaxation 
>   with only fixed lattice constant a?
>
>   In other words, lattice constant a is fixed; c  and atomic position will
>   be optimized. 

a simple way is to fix also c and perform a structural optimization 
at fixed cell; then vary c. 

Paolo

-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
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