Hi Pietro, thanks for the response. But how is the second alat value, within the <output> section in data-file-schema.xml, calculated? Is it just copied from celldm(1) and that's why the value is always the same as celldm(1)? Ryky
On Fri, Oct 5, 2018 at 1:05 PM Pietro Delugas <[email protected]> wrote: > Hello > > the input is generated following to the schema and expects only lattice > vectors in bohr units. > > The presence of alat and bravais_index attributes is optional and > indicates that the cell vectors were generated with the same algorithm used > in the latgen routine. > > In the case on ibrav = 0 cell vectors are arbitrarily defined by the > user, the routine which writes the xml file computes alat as the modulus > of the first cell vector, but it is probably better not to write it at all. > > In the other cases you mentioned the celldm(1) provided in input was > probably equal to the modulus of the first cell_vector. Or celldm(1) was > not provided at all in which case alat is computed as the modulus of the > first cell vector. > > By the way in CELL PARAMETERS it is also possible to specify angstroms as > units instead of alat and avoid to use celldm(1) > > > thanks for reporting the case > > best regards > > Pietro > > On 05/10/2018 10:39, Ryky Nelson wrote: > > Hi all, > > some user gave me the following setup of the input file for the namelist > SYSTEM and the card CELL_PARAMETERS > > &SYSTEM > ibrav = 0, > celldm(1) = 1.8897265, > nat = 4, > ntyp = 3, > ecutwfc = 70, > ecutrho = 560, > nbnd = 38, > / > CELL_PARAMETERS {alat} > 3.124623266 -3.124623266 0.000000000 > -3.124623266 0.000000000 -3.124623266 > 3.124623266 3.124623266 0.000000000 > > After finishing the calculation with QE 6.3 with the above setup, > strangely I got two alat values in data-file-schema.xml that are different > from each other; the first alat value, which is put inside the section > <input>, is 8.350483329220e0 and the other one, which is inside <output>, > is 1.889726500000e0 [which is equal to celldm(1)]. Could any one tell me > why they are different? My guess is that it has to do with the > CELL_PARAMETERS setup; since it's in {alat}, the elements are supposed > between -1 & 1, and previously, with other cases using this [-1,1] setup in > {alat}, I always got the same alat values from the <input> & <output> > sections? But Could any one tell me the exact reason? Thanks! > > Ryky > > > _______________________________________________ > users mailing > [email protected]https://lists.quantum-espresso.org/mailman/listinfo/users > > > _______________________________________________ > users mailing list > [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users
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