<div dir="ltr">Hi All, I am trying to do cell optimization of a SiS2 crystal structure which has a triclinic symmetry. Below is the section of input file where I specify the cell vectors and the angles: &SUBSYS &CELL SYMMETRY TRICLINIC A 5.58515 0.00000 0.00000 B 0.00000 6.21427 0.00000 C 0.00000 0.00000 10.92676 ALPHA_BETA_GAMMA 116.86 113.96 90.00 PERIODIC XYZ &END ! unit cells that are orthorhombic are more efficient with CP2K ! atom coordinates can be in the &COORD section, ! or provided as an external file. &TOPOLOGY COORD_FILE_FORMAT PDB COORD_FILE_NAME SiS2_computed.pdb CONNECTIVITY OFF &CENTER_COORDINATES &END CENTER_COORDINATES &END When I try to run the calculations, in the output file I can see the correct vectors a,b and c but the angles are still 90.0 90.0 and 90.0. Below is the portion from output file: CELL_TOP| Volume [angstrom^3]: 379.242 CELL_TOP| Vector a [angstrom 5.585 0.000 0.000 |a| = 5.585 CELL_TOP| Vector b [angstrom 0.000 6.214 0.000 |b| = 6.214 CELL_TOP| Vector c [angstrom 0.000 0.000 10.927 |c| = 10.927 CELL_TOP| Angle (b,c), alpha [degree]: 90.000 CELL_TOP| Angle (a,c), beta [degree]: 90.000 CELL_TOP| Angle (a,b), gamma [degree]: 90.000 CELL_TOP| Requested initial symmetry: TRICLINIC CELL_TOP| Numerically orthorhombic: YES CELL| Volume [angstrom^3]: 379.242 CELL| Vector a [angstrom]: 5.585 0.000 0.000 |a| = 5.585 CELL| Vector b [angstrom]: 0.000 6.214 0.000 |b| = 6.214 CELL| Vector c [angstrom]: 0.000 0.000 10.927 |c| = 10.927 CELL| Angle (b,c), alpha [degree]: 90.000 CELL| Angle (a,c), beta [degree]: 90.000 CELL| Angle (a,b), gamma [degree]: 90.000 CELL| Requested initial symmetry: TRICLINIC CELL| Numerically orthorhombic: YES CELL_REF| Volume [angstrom^3]: 379.242 CELL_REF| Vector a [angstrom 5.585 0.000 0.000 |a| = 5.585 CELL_REF| Vector b [angstrom 0.000 6.214 0.000 |b| = 6.214 CELL_REF| Vector c [angstrom 0.000 0.000 10.927 |c| = 10.927 CELL_REF| Angle (b,c), alpha [degree]: 90.000 CELL_REF| Angle (a,c), beta [degree]: 90.000 CELL_REF| Angle (a,b), gamma [degree]: 90.000 CELL_REF| Requested initial symmetry: TRICLINIC CELL_REF| Numerically orthorhombic: YES Because of this the complete geometry of the cell has changed during the optimization giving me weird results. Please find attached input files as well as the coordinate file. Kindly let me know how to fix the issue. Regards, Aniruddha M Dive PhD Candidate, Washington State University </div>