pycalphad
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20 hours ago •
pycalphad
pycalphad
ChemSage DAT support: parsing heat capacity parameters
DAT files allow for giving an H298, S298, and Cp polynomial terms to construct the Gibbs energy. When there are multiple temperature intervals, each new interval needs to provide a H_transformation and S_transformation as well as the Cp polynomial terms.
To add parameters specified this way to a pycalphad database, we need to integrate the heat capacity parameters to obtain H and S and combine them to compute (symbolically) G = H - TS that is piecewise in temperature.
Currently, the DAT parser can parse the heat capacity intervals, but will raise an error when converting parsed heat capacity intervals to symbolic piecewise intervals (implementing the pycalphad.io.cs_dat.IntervalCP class). There are two issues at play:
- SymEngine does not provide symbolic integration. For the DAT-prescribe polynomial terms (
CP_TERMS = (S.Zero, S.One, v.T, v.T**2, v.T**(-2))), we should be able to hardcode analytical antiderivatives of the heat capacity temperature terms (particularly where the power rule does not apply, e.g. the S.One term that gives a T**(-1) term in the entropy integral) as they relate to Gibbs energy. The DAT file also allows users to provide their own coefficient-exponent pairs that we won't be able to hardcode integrals for, but the exponents will be a real number so we should be able to apply the power rule on the exponents and "evaluate" the integrals symbolically by plugging in the integration limits to the hardcoded+power-rule terms. - When there are multiple temperature limits, each temperature limit needs to include the integration of heat capacity terms (and inclusion of transformation enthalpy and entropy) from the preceding intervals. The way the code is written right now, the energy contribution for each temperature interval is computed in isolation. For the Cp-type parameters in the DAT file, each interval would have to know about all the preceding intervals to be able to integrate properly from 298 K up until the temperatures in the current interval. Some things may have to be re-designed a little regarding how piecewise Gibbs energy expressions are constructed.
The DAT file below is mentioned in the ChemApp documentation and has heat capacity terms that can be used for testing
C-N-O See commentary below ! GTT 16/09/97
3 1 28 2
C N O
12.0110 14.0067 15.9994
6 1 2 3 4 5 6
4 1 2 3 4
GAS
IDMX
C
7 3 1.0 0.0 0.0
716680.00 158.09900
3400.0000 20.975300 -.39964699E-03 0.20077000E-06 -3361.3000
0.00000000
10000.000 23.050699 0.12092100E-03 -.40457500E-08 -17116500.
0.00000000
20000.000 19.445299 0.30792100E-03 0.36924100E-09 0.11237700E+09
C2
7 4 2.0 0.0 0.0
830457.00 197.09500
500.00000 97.481400 -.16406000 0.11841400E-03 -1381500.0
0.00000000
4300.0000 30.083500 0.52427799E-02 -.49857601E-06 1737000.0
0.00000000
12000.000 27.969601 0.38818000E-02 -.19335900E-06 44760100.
0.00000000
20000.000 86.666603 -.31285000E-02 0.43685599E-07 -.12092200E+10
C3
7 5 3.0 0.0 0.0
839958.00 237.61000
1000.0000 32.215599 0.29097101E-01 -.10668400E-04 200555.00
0.00000000
2800.0000 59.939800 -.50827898E-02 0.15248399E-05 -5538910.0
0.00000000
5100.0000 -7.2863898 0.20966399E-01 -.12041700E-05 0.11744000E+09
0.00000000
8000.0000 60.731098 0.95443502E-02 -.83080499E-06 -.38919699E+09
0.00000000
10000.000 211.87399 -.18404599E-01 0.61829900E-06 -.16880399E+10
C4
7 3 4.0 0.0 0.0
1033920.0 252.85600
2500.0000 53.395401 0.27995300E-01 -.49561600E-05 -362017.00
0.00000000
7000.0000 106.17400 -.33283301E-02 0.24180900E-06 -43813500.
0.00000000
10000.000 92.451797 0.53776300E-03 -.42438199E-07 -15174300.
C5
7 3 5.0 0.0 0.0
1050940.0 271.67200
900.00000 62.971901 0.63403003E-01 -.24581601E-04 -372551.00
0.00000000
3500.0000 106.59700 0.29567401E-02 -.42434201E-06 -7495690.0
0.00000000
10000.000 112.17100 0.13222300E-04 -.66332700E-09 -13131600.
CN
7 6 1.0 1.0 0.0
440287.00 202.64301
1000.0000 23.311701 0.13630500E-01 -.36727999E-05 188321.00
0.00000000
2800.0000 32.865898 0.13884200E-02 0.58599801E-06 -1381760.0
0.00000000
5500.0000 35.624802 0.45816898E-02 -.44317400E-06 -29864200.
0.00000000
9800.0000 49.662998 -.10938901E-02 0.10360400E-06 -10523900.
0.00000000
19000.000 26.034599 0.32982901E-02 -.10904700E-06 86173200.
0.00000000
20000.000 70.670502 -.40738899E-03 -.23514801E-07 -.17567300E+10
CN2_CNN
7 2 1.0 2.0 0.0
633484.00 232.08701
1500.0000 37.080898 0.24793999E-01 -.59896302E-05 -145473.00
0.00000000
6000.0000 69.647003 -.18004900E-02 0.13017301E-06 -14647200.
CN2_NCN
7 3 1.0 2.0 0.0
500535.00 226.22900
700.00000 22.682100 0.74644603E-01 -.37100399E-04 68821.203
0.00000000
1900.0000 65.881699 -.16084200E-03 -.35964300E-06 -4262720.0
0.00000000
6000.0000 64.095901 -.50357298E-03 0.41227899E-07 -687544.00
C2N_CCN
7 3 2.0 1.0 0.0
804806.00 239.02901
900.00000 36.285400 0.36251500E-01 -.15046300E-04 -105900.00
0.00000000
5300.0000 59.165699 0.13928399E-02 -.79184099E-08 -3093670.0
0.00000000
6000.0000 54.098099 0.31922900E-02 -.18162299E-06 8301570.0
C2N_CNC
7 3 2.0 1.0 0.0
684924.00 233.81900
800.00000 35.192699 0.41986100E-01 -.19222200E-04 -85784.703
0.00000000
4000.0000 60.762402 0.80248498E-03 -.10756100E-06 -3195470.0
0.00000000
6000.0000 62.406399 -.13479100E-04 0.10161200E-08 -5052510.0
CNO
7 3 1.0 1.0 1.0
177496.00 232.38100
900.00000 30.857500 0.41810598E-01 -.16743699E-04 -154913.00
0.00000000
3300.0000 58.688599 0.19923300E-02 -.29848300E-06 -4462280.0
0.00000000
6000.0000 62.265900 0.21348900E-04 -.14226700E-08 -7807020.0
CNO_NCO
7 3 1.0 1.0 1.0
159410.00 232.22099
800.00000 28.862801 0.47146101E-01 -.20431900E-04 -92762.602
0.00000000
2000.0000 53.999100 0.63656601E-02 -.13898500E-05 -3099870.0
0.00000000
6000.0000 63.381302 -.60019898E-03 0.92913197E-07 -8626740.0
CO
7 3 1.0 0.0 1.0
-110529.00 197.66499
800.00000 25.846201 0.65631098E-02 0.98167504E-06 111208.00
0.00000000
2200.0000 29.936600 0.54106200E-02 -.10533500E-05 -1082960.0
0.00000000
6000.0000 37.175900 0.20404700E-03 0.38694901E-08 -5448030.0
CO2
7 4 1.0 0.0 2.0
-393510.00 213.78300
900.00000 29.329599 0.39927199E-01 -.14750300E-04 -248862.00
0.00000000
2700.0000 54.438499 0.51133898E-02 -.80510500E-06 -4358740.0
0.00000000
7600.0000 76.003403 -.52149598E-02 0.64008100E-06 -35080900.
0.00000000
10000.000 -85.621300 0.24522400E-01 -.90525100E-06 0.14018900E+10
C2O
7 3 2.0 0.0 1.0
291043.00 233.60800
1000.0000 37.785702 0.29073700E-01 -.94620900E-05 -225213.00
0.00000000
3500.0000 56.629601 0.52282899E-02 -.59135601E-06 -4096730.0
0.00000000
6000.0000 68.436699 0.97912597E-03 -.14914700E-06 -32900900.
N
7 2 0.0 1.0 0.0
472687.00 153.29800
2950.0000 20.893900 -.16910399E-03 0.60112100E-07 -5577.5698
0.00000000
6000.0000 16.376101 0.45674801E-03 0.16739800E-06 15118200.
N2
7 3 0.0 2.0 0.0
0.00000000 191.61099
800.00000 27.223301 0.25198299E-02 0.32362900E-05 76653.398
0.00000000
2200.0000 28.423800 0.63785501E-02 -.12398300E-05 -833938.00
0.00000000
6000.0000 37.550098 0.12318000E-04 0.25352801E-07 -6855020.0
N3
7 3 0.0 3.0 0.0
436000.00 223.06599
800.00000 24.401800 0.50211601E-01 -.20478799E-04 -123306.00
0.00000000
2200.0000 52.349899 0.71044699E-02 -.14389200E-05 -3738980.0
0.00000000
6000.0000 61.964901 0.11107600E-03 -.88627798E-08 -9309660.0
NO
7 5 0.0 1.0 1.0
91277.000 210.74500
1300.0000 23.051201 0.15473500E-01 -.47752401E-05 233303.00
0.00000000
5500.0000 37.556301 -.51918800E-04 0.60612400E-07 -3986150.0
0.00000000
9800.0000 13.212000 0.37948100E-02 -.64632999E-07 0.20715299E+09
0.00000000
14500.000 4.4607501 0.72746398E-02 -.28647401E-06 -.18147400E+09
0.00000000
20000.000 170.93600 -.86434204E-02 0.14216199E-06 -.56028498E+10
NO2
7 3 0.0 1.0 2.0
34193.000 240.16600
800.00000 22.650000 0.52844901E-01 -.22859200E-04 70594.102
0.00000000
2400.0000 54.239700 0.28189200E-02 -.15991800E-06 -3832450.0
0.00000000
6000.0000 46.444000 0.47797300E-02 -.96086502E-07 11854400.
NO3
7 3 0.0 1.0 3.0
71128.000 252.62199
600.00000 13.982300 0.14200200 -.87225097E-04 -143564.00
0.00000000
1300.0000 69.838501 0.14972700E-01 -.48511401E-05 -3489250.0
0.00000000
6000.0000 82.856201 0.95063398E-04 -.83041503E-08 -6635110.0
N2O
7 3 0.0 2.0 1.0
81600.000 220.00500
900.00000 31.214800 0.38315602E-01 -.14092900E-04 -246006.00
0.00000000
2900.0000 55.975101 0.42720600E-02 -.57106701E-06 -4357220.0
0.00000000
6000.0000 62.137299 0.62846800E-03 0.26556201E-07 -9580270.0
N2O3
7 3 0.0 2.0 3.0
86631.000 314.73401
900.00000 56.690399 0.62969401E-01 -.25171499E-04 -45424.500
0.00000000
3600.0000 100.38500 0.13410100E-02 -.55178301E-07 -6993170.0
0.00000000
6000.0000 93.545403 0.34843700E-02 -.22545800E-06 10275000.
N2O4
7 3 0.0 2.0 4.0
11110.000 304.44501
700.00000 54.510300 0.12472000 -.61755600E-04 -627855.00
0.00000000
2400.0000 121.09400 0.57820301E-02 -.11838400E-05 -7002920.0
0.00000000
6000.0000 128.78999 0.22902101E-04 -.17693800E-08 -10930000.
N2O5
7 3 0.0 2.0 5.0
13300.000 355.71701
800.00000 76.767700 0.10727900 -.47430101E-04 -820876.00
0.00000000
3000.0000 141.33299 0.50176601E-02 -.83227502E-06 -8874420.0
0.00000000
6000.0000 149.48500 0.40587100E-04 -.27888700E-08 -15036600.
O
7 2 0.0 0.0 1.0
249174.00 161.06000
2950.0000 21.015600 -.25374099E-03 0.73878802E-07 85794.203
0.00000000
6000.0000 17.211901 0.10827100E-02 -.45871200E-07 7946340.0
O2
7 5 0.0 0.0 2.0
0.00000000 205.14700
900.00000 22.258600 0.20477301E-01 -.80396803E-05 153499.00
0.00000000
3700.0000 33.557301 0.24697999E-02 -.10016600E-06 -1079770.0
0.00000000
9600.0000 24.479799 0.52695200E-02 -.36092700E-06 30241900.
0.00000000
18500.000 87.561401 -.51574502E-02 0.11272600E-06 -.58104998E+09
0.00000000
20000.000 63.737000 -.28750000E-02 0.54000001E-07 -.50307798
O3
7 7 0.0 0.0 3.0
141800.00 239.00500
700.00000 27.581200 0.55261500E-01 -.27632401E-04 -199061.00
0.00000000
1300.0000 60.102901 -.41291201E-02 0.31049201E-05 -3144350.0
0.00000000
2100.0000 134.37000 -.79414703E-01 0.24627499E-04 -24724500.
0.00000000
2800.0000 -421.20001 0.25682199 -.32686101E-04 0.42609699E+09
0.00000000
3500.0000 -223.44400 0.18447199 -.25841100E-04 43179700.
0.00000000
4900.0000 764.84302 -.19705500 0.15587100E-04 -.19221700E+10
0.00000000
6000.0000 149.96100 -.25671501E-01 0.21330600E-05 0.43400000E+09
C_DIAMOND_A4
4 1 1.0 0.0 0.0
6000.0000 -16359.441 175.61000 -24.310000 -.47230000E-03
0.00000000 2698000.0
2 -.26100000E+09 -2.0 0.11100000E+11 -3.0
C
7 3 1.0 0.0 0.0
0.00000000 5.6859999
800.00000 -3.0257599 0.47484200E-01 -.23528601E-04 -45617.301
0.00000000
1900.0000 20.021799 0.48779999E-02 -.11859501E-05 -2133160.0
0.00000000
6000.0000 25.499001 -.19641699E-03 0.95123198E-07 -3795520.0
#############################################################################
Date : 16.09.1997
Originator : KH
Serial No : CNO.DAT
Quality Status : A
ChemSage Vers. : 4.0
Temperatures : All
Compositions : All
Applications : Combustion equilibria and thermodynamic properties of
the gas species and condensed phases.
Sources of data
Unary : 96SGT and 91Din
Binary : None
References : 91Din Dinsdale,A.T. CALPHAD 15(4), 1991, 317-427
96SGT SGTE Pure Substance database, Edition 1996
###########################################################################
