LORBIT

Available up from VASP version 3.2. In VASP.3.2 ORBIT can be either .TRUE. or .FALSE. In VASP.4.X LORBIT can also take integer values:

logical	integer	RWIGS line in INCAR	files written
.FALSE.	0	line required	DOSCAR and PROCAR file
	1	line required	DOSCAR and extended PROCAR file
.TRUE.	2	line required	DOSCAR and PROOUT file
	10	not read	DOSCAR and PROCAR file
	11	not read	DOSCAR and PROCAR file with phase factors
	12		not supported

VASP.4.6 behaviour:

integer	RWIGS line in INCAR	files written
0	line required	DOSCAR and PROCAR file
1	line required	DOSCAR and lm decomposed PROCAR file
2	line required	DOSCAR and lm decomposed PROCAR file + phase factors
5	line required	PROOUT file
10	not read	DOSCAR and PROCAR file
11	not read	DOSCAR and lm decomposed PROCAR file
12	not read	DOSCAR and lm decomposed PROCAR file + phase factors

The default for LORBIT is .FALSE. (respectively 0).

This flag determines, together with an appropriate RWIGS (see section 6.32), whether the PROCAR or PROOUT files (see section 5.21) are written. The file PROCAR contains the spd- and site projected wave function character of each band. The wave function character is calculated, either by projecting the wavefunctions onto spherical harmonics that are non zero within spheres of a radius RWIGS around each ion (LORIT=1, 2), or using a quick projection scheme relying that works only for the PAW method (LORBIT=10,11,12, see below). If the LORBIT flag is not equal zero, the site and l-projected density of states is also calculated.

The PROOUT file (LORBIT=2) contains the projection of the wavefunctions onto spherical harmonics centered at the position of the ions ( $P_{Nlmn {\bf k}}\equiv \langle Y_{lm}^{N}\vert\phi_{n{\bf k}}\rangle$) and the corresponding augmentation part.

This information can be used to construct e.g. the partial DOS projected onto molecular orbitals or the so-called coop ( crystal overlap population function). Mind, that in VASP.4.5 (and later releases), two PROOUT files are generated one for spin up (PROOUT.1) and one for spin down (PROOUT.2). For a non spin polarised calculation only PROOUT.1 is generated.

If the projector augmented wave method is used, LORBIT can also be set to 10, 11 or 12. This alternative setting selects a quick method for the determination of the spd- and site projected wave function character and does not require the specification of a Wigner-Seitz radius in the INCAR file (the RWIGS line is neglected in this case). The method works only for PAW POTCAR files and not for ultrasoft or norm conserving pseudopotentials.

The parallel version has some restrictions: The site projected DOS is not evaluated in the parallel version in the following cases:

VASP.4.5, NPAR$\ne$1	no site projected DOS
VASP.4.6, NPAR$\ne$1, LORBIT=0-5	no site projected DOS