[Pw_forum] vc-relax - negative and non-zero cell parameters

[Paolo Giannozzi]

On Fri, 2011-05-20 at 14:02 +0100, Christopher Heard wrote:

> My problem is that it makes no sense to me that off diagonal elements can be non-zero, when they are relative.

> CELL_PARAMETERS (alat= 30.23000000)
>   1.003485881   0.000341145  -0.000166335
>   0.000341140   1.002476151   0.000847099
>  -0.000166325   0.000846982   1.001936910

lattice vector 1 : (1.003485881   0.000341145  -0.000166335)*alat
lattice vector 2 : (0.000341140   1.002476151   0.000847099)*alat
lattice vector 3 : (-0.000166325  0.000846982   1.001936910)*alat

Where is the problem?
-- 
Paolo Giannozzi, IOM-Democritos and University of Udine, Italy