SeqQuest Atom Library

Overview

SeqQuest requires pseudopotentials and Gaussian basis sets for every atom type in a given calculation. These pseudopotentials are not generated within Quest itself: the Gaussian basis sets are atom- and potential-specific and must be provided. Quest accesses the pseudopotentials and associated basis sets it uses from atom files that have been previously generated, and collected into libraries. This page summarizes the availability of atom files for the various functionals available in the code.

One should not mix different functionals in the atom pseudopotential generation and SeqQuest calculations. If necessary, it is probably safe to use PBE atoms in PW91 calculations given the close correspondence of these two functionals, but we recommend simply keeping to PBE calculations.

The code uses non-local ("semi-local" in common physics jargon) norm-conserving pseudopotentials (not "ultra-soft" nor "separable" potentials). All the pseudopotentials currently in the libraries are either of the Hamann type or the Troullier/Martins type. The pseudopotentials are generally constructed to be very "hard" to ensure maximum transferability. Compromising the transferability of the PP for greater softness is unnecessary, as the cost of a local orbital calculation is relatively insensitive to the PP,

For each available atom of a given pseudopotential and given DFT functional, a Gaussian basis set is provided. Development of effective basis sets is something of an art. The basis sets for Quest are carefully optimized pseudo-variationally, refined and tested in chemical environments representative of typical expected Quest use. Users should check internal documentation of atom files for basis author. These basis sets are intended for periodic calculations. The basis design avoids the very diffuse gaussians that can lead to linear dependence (but can become linearly dependent under significant compressions). Ghost atoms (or "floating orbitals"), basis sets without atomic potentials, are also possible, to augment the atom-centered basis (e.g. to get more accurate work functions for slab surfaces).

SeqQuest LDA Atom Library

1 H				III-V, II-VI terminators <!– Z = 1/2, 3/4, 5/4, 3/2 –> Z = 1⁄2, 3⁄4, 5⁄4, 3⁄2																2 He
3 Li	4 Be													5 B	6 C	7 N	8 O	9 F		10 Ne
11 Na	12 Mg													13 Al	14 Si	15 P	16 S	17 Cl		18 Ar
19 K	20 Ca		21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn		31 Ga	32 Ge	33 As	34 Se	35 Br		36 Kr
37 Rb	38 Sr		39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd		49 In	50 Sn	51 Sb	52 Te	53 I		54 Xe
55 Cs	56 Ba	57 La	*	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg		81 Tl	82 Pb	83 Bi	84 Po	85 At		86 Rn
87 Fr	88 Ra	89 Ac
		*	58 Ce3 Ce4	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu2 Eu3	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb2 Yb3	71 Lu
				Legend:			68 Er	Available atom						84 Po	No atom file

All LDA atom file (pseudopotential and associated basis sets) are developed by Peter A. Schultz (Sandia),

• P.A. Schultz, unpublished.

All LDA potentials are Hamann type norm-conserving pseudopotentials,

• D.R. Hamann, Phys. Rev. B 40, 2980 (1989),

except for N,C,O,F,Ni,Cu,Zn, and Ga(d¹⁰) which use the Troullier/Martins type,

• N. Troullier and J.L. Martins, Phys. Rev. B 43, 1993 (1991),

and use of these atom files should cite the appropriate reference.

Also, alkali atoms, alkaline earths, and several early transition metals atoms and early main group atoms incorporate the partial core correction:

• S.G. Louie, S. Froyen, and M.L. Cohen, Phys. Rev. B 26 1738 (1982).

SeqQuest PBE Atom Library

1 H				III-V, II-VI terminators <!– Z = 1/2, 3/4, 5/4, 3/2 –> Z = 1⁄2, 3⁄4, 5⁄4, 3⁄2																2 He
3 Li	4 Be													5 B	6 C	7 N	8 O	9 F		10 Ne
11 Na	12 Mg													13 Al	14 Si	15 P	16 S	17 Cl		18 Ar
19 K	20 Ca		21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn		31 Ga	32 Ge	33 As	34 Se	35 Br		36 Kr
37 Rb	38 Sr		39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd		49 In	50 Sn	51 Sb	52 Te	53 I		54 Xe
55 Cs	56 Ba	57 La	*	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg		81 Tl	82 Pb	83 Bi	84 Po	85 At		86 Rn
87 Fr	88 Ra	89 Ac
		*	58 Ce3 Ce4	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu2 Eu3	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb2 Yb3	71 Lu
				Legend:			68 Er	Available atom						84 Po	No atom file

All PBE pseudopotentials were generated using the Fritz-Haber Institute fhi98PP code:

• M. Fuchs and M. Scheffler, Comput. Phys. Commun. 119, 67 (1999)

and either employ the Hamann type of norm-conserving pseudopotential,

• D.R. Hamann, Phys. Rev. B 40, 2980 (1989),

or the Troullier/Martins type,

• N. Troullier and J.L. Martins, Phys. Rev. B 43, 1993 (1991).

For older (now retired) silicon and hydrogen pseudopotentials, P.A. Schultz used D.R Hamann’s new method for generating pseudopotentials (especially developed to handle the pathologies that GGA functionals inject into pseudopotentials) that Don Hamann very generously provided:

• D.R. Hamann, unpublished.

Also, alkali atoms, alkaline earths, and several early transition metals atoms and early main group atoms incorporate the partial core correction:

• S.G. Louie, S. Froyen, and M.L. Cohen, Phys. Rev. B 26 1738 (1982).

Please check internal documentation of atom files, and cite the appropriate references in any publications.

SeqQuest AM05 Atom Library

1 H																				2 He
3 Li	4 Be													5 B	6 C	7 N	8 O	9 F		10 Ne
11 Na	12 Mg													13 Al	14 Si	15 P	16 S	17 Cl		18 Ar
19 K	20 Ca		21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn		31 Ga	32 Ge	33 As	34 Se	35 Br		36 Kr
37 Rb	38 Sr		39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd		49 In	50 Sn	51 Sb	52 Te	53 I		54 Xe
55 Cs	56 Ba	57 La		72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg		81 Tl	82 Pb	83 Bi	84 Po	85 At		86 Rn
87 Fr	88 Ra	89 Ac
				Legend:			8 O	Available atom						54 Xe	No atom file

All AM05 pseudopotentials are generated using the Fritz-Haber Institute fhi98PP code:

• M. Fuchs and M. Scheffler, Comput. Phys. Commun. 119, 67 (1999)

and either employ the Hamann type of norm-conserving pseudopotential,

• D.R. Hamann, Phys. Rev. B 40, 2980 (1989),

or the Troullier/Martins type,

• N. Troullier and J.L. Martins, Phys. Rev. B 43, 1993 (1991).

Also, alkali atoms, alkaline earths, and several early transition metals atoms and early main group atoms incorporate the partial core correction:

• S.G. Louie, S. Froyen, and M.L. Cohen, Phys. Rev. B 26 1738 (1982).

Please check internal documentation of atom files, and cite the appropriate references in any publications.

SeqQuest BLYP Atom Library

1 H																				2 He
3 Li	4 Be													5 B	6 C	7 N	8 O	9 F		10 Ne
11 Na	12 Mg													13 Al	14 Si	15 P	16 S	17 Cl		18 Ar
19 K	20 Ca		21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn		31 Ga	32 Ge	33 As	34 Se	35 Br		36 Kr
37 Rb	38 Sr		39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd		49 In	50 Sn	51 Sb	52 Te	53 I		54 Xe
55 Cs	56 Ba	57 La		72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg		81 Tl	82 Pb	83 Bi	84 Po	85 At		86 Rn
87 Fr	88 Ra	89 Ac
				Legend:			8 O	Available atom						54 Xe	No atom file

All BLYP pseudopotentials are generated using the Fritz-Haber Institute fhi98PP code:

• M. Fuchs and M. Scheffler, Comput. Phys. Commun. 119, 67 (1999)

and either employ the Hamann type of norm-conserving pseudopotential,

• D.R. Hamann, Phys. Rev. B 40, 2980 (1989),

or the Troullier/Martins type,

• N. Troullier and J.L. Martins, Phys. Rev. B 43, 1993 (1991).

Also, alkali atoms, alkaline earths, and several early transition metals atoms and early main group atoms incorporate the partial core correction:

• S.G. Louie, S. Froyen, and M.L. Cohen, Phys. Rev. B 26 1738 (1982).

Please check internal documentation of atom files, and cite the appropriate references in any publications.