Condensation in Dust-enriched Systems, by D.S. Ebel and L. Grossman,
Geochimica et Cosmochimica Acta, 1999

Technique: Thermodynamic Data for Elements and Gas Species

In each calculation, 23 elements were included: H, He, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Ti, Cr, Mn, Fe, Co and Ni. The gas species considered in every calculation include all species considered by Grossman (1972) and Yoneda and Grossman (1995), as well as those listed in Table 2. The (delta)_fH^o(298.15K), S^o(298.15K) and C_p^o(T) data for gas species and elements in their standard states were taken wherever possible from the JANAF tables (Chase et al., 1985), obtained in machine readable form from the National Institute of Standards and Technology in 1995. For a few gas species not present in the JANAF database, data from Knacke et al. (1991) or Pedley and Marshall (1983) were used. During calculation, apparent Gibbs energies of formation (Anderson and Crerar, 1993), and hence the equilibrium constants of reactions, were calculated by integration of polynomial fits to tabulated C_p^o(T) data. Errors were found in the JANAF tabulations (Chase et al., 1985) of the Gibbs energy of formation ((delta)_fG^o)and equilibrium constant (lnK_f) for the gas species C₂N₂, C₂H₂, CN, and HS. The error in HS was also present in the electronic version, and had not been previously reported (M. Chase, pers. comm; 1996). Although it does not occur in the tabulations of Stull and Prophet (1970), Barin (1989), or Knacke et al. (1991), the HS_(g) error has been propagated through the work of Yoneda and Grossman (1995), and probably also Sharp and Wasserburg (1995) and others. The effect of this error is to overestimate the stability of HS_(g), and cause SiS_(g) to sequester slightly less Si than it should.

Chase et al. (1985)					Knacke et al.
Table 2. Gas species and thermodynamic data sources included in the calculation, in addition to species used by Grossman (1972) and/or Yoneda and Grossman (1995).
					(1991)
Ne	CHClF₂	NiCl	CoF₂	F₃NO
Ar	CHCl₂F	ClO	CrN	PF₃O	CrCl₂O₂
AlClF	CHCl₃	TiOCl	CrO	PF₃	MnCl₂
AlClF₂	CHF	ClO₂	CrO₂	F₃PS	CrS
AlCl₂	CHFO	PCl	CrO₃	SF₃	MnF₂
AlCl₂F	CHF₃	ClS	F10S₂	SiF₃	NiF₂
AlCl₃	CH₂ClF	ClS₂	FeF	TiF₃	Ni(OH)₂
AlF₂	CH₂Cl₂	SiCl	FHO	H₄F₄	NiO
AlF₂O	CH₂F₂	TiCl	FHO₃S	Mg₂F₄	NiAl₂Cl₈
AlF₃	CH₃Cl	Cl₂	SiFH₃	N₂F₄	NiF
NaAlF₄	CH₃F	Co Cl₂	SiF₃H	SF4	NiH
AlHO	KCN	Cl₂FOP	FNO	SiF₄	TiS
Al₂	CN₂^a	FeCl₂	FNO₂	TiF₄	CrCl₂
Al₂Cl₆	CP	SiCl₂H₂	FNO₃	TiFO
Al₂F₆	C₂Cl₂	K₂Cl₂	FO	PF₅	Pedley & Marshall
CCl	C₂Cl₄	C₂Cl₄	Na₂Cl₂	H₅F₅	(1983)
CClFO	C₂Cl₆	NiCl₂	FO₂	H₆F₆
CClF₃	C₂F₂	Cl₂O	FPS	SF₆	CoO
CClN	C₂F₄	TiCl₂O	SF	H₇F₇	MnO
CClO	C₂F₆	Cl₂O₂S	SiF	FeS
CCl₂	C₂HCl	Cl₂S	F₂	HNO₂^a
CCl₂F₂	C₂HF	Cl₂S₂	FeF₂	K₂O₂H₂
CCl₂O	C₂H₄	SiCl₂	H₂F₂	KO
CCl₃	(KCN)₂	TiCl₂	K₂F₂	K₂
CCl₃F	Ni(CO)₄	CoCl₃	F₂N	K₂SO₄
CCl₄	Fe(CO)₅	SiCl₃F	F₂N2a	Na₂SO₄
CF	CaCl	FeCl₃	Na₂F₂	NiS
CFN	CaS	SiCl₃H	F₂O	P₄O10
CFO	CoCl	POCl₃	SiF₂O	P₄O₆
CF₂	ClF	PCl₃	TiF₂O	P₄
CF₂O	ClFO₂S	PCl₃S	SF₂O₂	P₄S₃
CF₃	ClFO₃	TiCl₃	PF₂	S₃
CF₄	ClF₂OP	Co₂Cl₄	SF₂	S₄
CF₄O	ClF₃	Fe₂Cl₄	S₂F2a	S₅
CF₈S	ClF₅	Mg₂Cl₄	SiF₂	S₆
CHCl	ClF₅S	SiCl₄	FeF₃	S₇
ClNO₂	FeCl	TiCl₄	SiF₂H₂
ClHO	PCl₅	SiCl₃	H₃F₃
ClNO	Fe₂Cl6	SiCl₃F	NF₃
--------------	--------------	--------------	--------------	--------------	--------------
notes: a) Both cis and trans forms are included.

CONDENSATION
in
DUST-ENRICHED SYSTEMS

Denton S. Ebel (1)

Lawrence Grossman(1,2)

(1) Department of The Geophysical Sciences
The University of Chicago
5734 South Ellis Ave.
Chicago, IL 60637

(2) Enrico Fermi Institute
The University of Chicago
5640 South Ellis Ave.
Chicago, IL 60637

Submitted December 22, 1998 to

Geochimica et Cosmochimica Acta

Revised version submitted June 30, 1999

Abstract

Introduction
Technique

Bulk Composition

Method of Calculation

Data for Elements and Gas Species

Data and Models for Solids

Data and Models for Silicate Liquids

Test of MELTS: Peridotite KLB-1

Transition Between Liquid Models

Results

Vapor of Solar Composition

General Effects of Dust Enrichment and Total Pressure