RWIGS：Wigner Seitz radius

可选参数。对一个有两种原子的系统，必须对每种都给定一个，即
RWIGS = 1.0 1.5
If the RWIGS values is supplied, the spd- and site projected wave function character of each band is evaluted, and the local partial DOS is calculated (see sections 5.16 and 5.15).

对单电子体系 RWIGS can be de£ned unambiguously. the spheres around each atom 的体积之和应与cell的总体积相同 (假设cell内没有真空层). This is in the spirit of atomic sphere calculations. VASP writes a line
Volume of Typ 1: 98.5 %
to the OUTCAR £le.

应使用RWIGS value which yields a volume of approximately 100%.

对 binary system there is no unambiguous way to de£ne RWIGS and several choices are possible. the spheres around each atom 的体积之和应与cell的总体积接近(即the sum of the values given by VASP should be around 100%).
• 一种选择是设置使spheres间重叠最小的RWIGS。

• 而大多数情况下, 更简单的方法是将每个sphere的半径设为与共有半径相似的值，而共有半径有表可查。 This simple criterion can be used in most cases, and it relies at least on some “physical intuition”.

注意所得结果是定性的 — i.e. there is no unambiguous way to determine the location of an electron. With the current implementation, it is for instance hardly possible to determine charge transfer. What can be derived from the partial DOS is the typical character of a peak in a DOS. 定量的结果can be obtained only by carefull comparison with
a reference system (e.g. bulk versus surface).

LORBIT

VASP.4.6 behaviour:
integer      RWIGS line in INCAR        files written
0            line required              DOSCAR and PROCAR £le
1            line required              DOSCAR and lm decomposed PROCAR £le
2            line required              DOSCAR and lm decomposed PROCAR £le + phase factors
5            line required              PROOUT £le
10           not read                   DOSCAR and PROCAR £le
11           not read                   DOSCAR and lm decomposed PROCAR £le
12           not read                   DOSCAR and lm decomposed PROCAR £le + phase factors

默认值是.FALSE. (respectively 0)。

This flag determines, together with an appropriate RWIGS (see section 7.29), whether the PROCAR or PROOUT £les (seesection 5.21) are written.

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). 若LORBIT 不为零, 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（Nlmnk） ≡ )(波函数在球谐函数上的投影） 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). 注意, 会生成两个PROOUT文件，one for spin up (PROOUT.1) and one for spin down (PROOUT.2). 对自旋非极化计算只生成PROOUT.1。

If the projector augmented wave（PAW) 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 不需要在INCAR中指定a Wigner-Seitz radius(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=1 no site projected DOS
vasp.4.6, NPAR=1, LORBIT=0-5 no site projected DOS