Methodology and Standards
Related Links
Some of the documents on this webpage may be in PDF Format. Please download the Free PDF reader from Adobe to view these files.
|
Updated:
23 May 2008
HCh specifications
(HCh for Windows)
HD space requirements
2Mb for the initial installation.
[back to top]
Operating systems
Windows 32 (9x, ME, NT, 2K, XP, Vista) operating systems;
Windows-emulating packages for the Macintosh computers.
Databases, chemical systems, phases and solutions
Databases
|
|
Number of user-defined databases:
|
Unlimited
|
|
Database usage:
|
One at a time
|
[back to top]
Data sources for the default database
Miscellaneous sources; partially based on SUPCRT 92
Database Components and Capacity
|
|
Stoichiometry units:
|
Chemical elements
|
105
<=150
|
Standard (conventional)
User-defined
|
|
Database components
|
Database capacity
|
Chemical compounds
|
Equation of state
|
|
Pure water
|
|
Pure water
|
Haar-Gallagher-Kell model (Kestin et al, 1984)
|
|
Basic species
|
1023
|
- Simple ions
- Polyatomic ions
- Aqueous complexes
|
The revised Helgeson-Kirkham-Flowers equations of state (MHKF) (Shock et al, 1992; Tanger and Helgeson, 1988)
|
|
Complexes*1
|
1023
|
- Aqueous complexes
- Polyatomic ions
|
The modified Ryzhenko-Bryzgalin model (Borisov and Shvarov, 1992) |
|
Pure phases |
1023 |
- Minerals
- Ideal gases
- Non-aqueous liquids
|
Conventional integration of heat-capacity equations*2 |
|
Gases |
1023 |
Gases |
Conventional integration of heat-capacity equations*2 +
Peng-Robinson Stryjek-Vera equation of state (Stryjek and Vera, 1986) |
|
Total |
4092 |
|
|
|
Note:
*1 Optional definition according to the isocoulombic approach by
Gu et al. (1994)
*2
- Cp(t)=a+b*T+c*T -2+d*T -0.5+e*T
2+f*T 3+g*T 4+h*T -3+i*T
0.5+j*T -1
- Allowed number of phase transitions in minerals: 4
- Maximum number of the Cp(t)equations: 5
- No provisions for calculation of mineral compressibilities
|
Limitations of chemical models |
|---|
|
Maximum number of chemical elements allowed in models: |
30 |
Allowed model phases and solution models |
|---|
|
Phases |
Maximum number of phases |
Solution model and calculation of activities |
Maximum number of components in the solution phase |
|
Pure solids (minerals, liquids, and gases) |
255 |
|
|
|
Solid solutions (ideal multi-site mixing) |
Unlimited |
Ideal:
- Molecular
- Mixing-on-sites (MOS,
4 sites allowed)
- Local charge balance (LCB)
|
255
21
21 |
|
Liquid non-aqueous solutions |
Unlimited |
- Ideal
- Non-random two-liquid (NRTL)
|
255
7 |
|
Gaseous mixture |
1 |
- Ideal
- Peng-Robinson Stryjek-Vera (PRSV)
|
255
7 |
|
Aqueous solution (including supercritical aqueous phase) |
1 |
Water: γ = 1 or according to the HKF model
(Helgeson et al., 1981); Charged species: extended versions of the Debye-Hückel equation
(Helgeson, 1969; Helgeson et al., 1981; Oelkers and Helgeson, 1990);
Neutral species: Setchénow equation (eg, Oelkers and Helgeson,
1990) |
255 |
Special Notes |
|---|
|
Recommended T-P range for systems containing aqueous solution: |
0-1000°C, 1-5000 bar at water densities exceeding 0.35
g/cm3 (according to the MHKF model) |
|
Allowed salinity range for systems containing aqueous solution: |
Limited by the applicability of the extended versions of the
Debye-Hückel equation; Computationally sensible results for I<10 M |
[back to top]
Related factsheets
[back to top]
Related links
|
