diff --git a/pw2poscar.txt b/pw2poscar.txt index 98cb900..4f536f6 100644 --- a/pw2poscar.txt +++ b/pw2poscar.txt @@ -10,11 +10,26 @@ From line 9 onwards write the position in the unit as defined in line 8. Sample file is as below for GaN crystal +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +GaN Crystal (4 atom basis) # this line is only comment (1st line) +1.0 # Lattice constant (adjusted by a vector) (2nd line) + 3.18 0.000 0.00 # a1 (3rd line) + -1.59 2.754 0.00 # a2 (4th line) + 0.000 0.000 5.166 # a3 (5th line) + Ga N # atomic symbols (6th line) + 2 2 # unmber of atoms (7th line) +Direct # Unit types Direct of Cartesian (only first character has meaning) (8th line) + 0.333333348 0.666666697 0.000000000 # position of Ga + 0.666666615 0.333333305 0.500000000 # position of Ga + 0.333333348 0.666666697 0.385000000 # position of N + 0.666666615 0.333333305 0.885000000 # position of N ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +Above file can also be written as changing line 2 and +++++++++++++++++++++++++++++++++++++++++++++++++++++++ GaN Crystal (4 atom basis) # this line is only comment -1.0 # Lattice constant (adjusted by a vector) - 3.1800000668 0.0000000000 0.0000000000 # a1 - -1.5900000334 2.7539608418 0.0000000000 # a2 - 0.0000000000 0.0000000000 5.1659998894 # a3 +3.18 # Lattice constant (adjusted by a1, a2 and a3 vectors) + 1.0000 0.000000 0.0000 # a1 + -1.5000 0.866025 0.0000 # a2 + 0.0000 0.000000 1.62453 # a3 Ga N # atomic symbols 2 2 # unmber of atoms Direct # Unit types Direct of Cartesian (only first character has meaning) @@ -22,5 +37,21 @@ Direct # Unit types Direct of Cartesian (only first character has meaning) 0.666666615 0.333333305 0.500000000 # position of Ga 0.333333348 0.666666697 0.385000000 # position of N 0.666666615 0.333333305 0.885000000 # position of N -+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + +PWscf input (only the crystal geometry part) of POSCAR file can be written as below: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +celldm(1) = 6.00933 ! 3.18/0.529177 in au. +CELL_PARAMETERS {alat} + 1.0000 0.000000 0.0000 ! a1 + -1.5000 0.866025 0.0000 ! a2 + 0.0000 0.000000 1.62453 ! a3 + ATOMIC_POSITIONS {crystal} + Ga 0.333333348 0.666666697 0.000000000 ! position of Ga + Ga 0.666666615 0.333333305 0.500000000 ! position of Ga + N 0.333333348 0.666666697 0.385000000 ! position of N + N 0.666666615 0.333333305 0.885000000 ! position of N + ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +On the PWscf input file order of atomic symbols sould be in the same as in ATOMIC_SPECIES block +