National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
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XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
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XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

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XVII.C.1. (III.D.6.)

Calculated Ionization Energy for Mg (Magnesium atom)

Experimental Ionization Energy is 7.64624 eV
Original data displayed. Press to display differences.
Differences displayed. Press to display original data.

Ionization Energies in eV
Methods with predefined basis sets
semi-empirical PM6  
composite G1 7.675
G2MP2 7.677
G2 7.648
G3 7.785
G3B3 7.799
G3MP2 7.753
G4 7.673
CBS-Q 7.592

Ionization Energies in eV
Methods with standard basis sets
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
hartree fock HF 1.105 6.599 6.606 6.614 6.606 6.606 6.606 6.605 6.605 6.612 6.605 6.605 6.611 6.624 6.607 6.606 6.624 6.607 6.606
density functional LSDA 3.365 7.480 8.140 8.175 8.153 8.153 8.153 8.157 8.157 8.162 8.157 8.157 8.168 8.183 8.153 8.153 8.183 8.153 8.153
SVWN 3.365 8.131 8.140 8.175 8.153 8.153 8.153 8.157 8.157 8.162 8.157 8.157 8.168 8.183 8.153 8.153 8.184 8.153 8.153
BLYP 2.759 7.653 7.655 7.653 7.632 7.632 7.632 7.631 7.631 7.641 7.632 7.632 7.647 7.661 7.633 7.631 7.662 7.632 7.631
B1B95 2.529 6.883 7.433 7.470 7.442 7.450 7.450     7.457 75.431 7.442 7.455 7.479 7.437 7.440   7.437 19.778
B3LYP 2.799 7.745 7.748 7.751 7.730 7.729 7.729 7.727 7.727 7.738 7.728 7.728 7.743 7.760 7.728 7.726 7.760 7.728 7.726
B3LYPultrafine 2.799 7.745 7.748 7.751 7.729 7.729 7.729 7.728 7.728 7.738 7.728 7.728 7.743 7.760 7.728 7.726 7.760 7.728 7.726
B3PW91 2.606 7.531 7.549 7.569 7.549 7.549 7.548 7.542 7.542 7.556 7.542 7.542 7.557 7.576 7.541 7.542 7.576 7.541 7.542
mPW1PW91 2.527 7.507 7.539 7.550 7.516 7.516 7.516 7.508 7.521 7.536 7.521 7.521 7.537 7.555 7.520 7.521 7.555 7.520 7.521
M06-2X 2.587 7.746 7.768 7.784 7.768 7.768 7.770 7.769 7.769 7.769 7.769 7.769 7.781 7.785 7.776 7.772 7.785 7.774 7.772
PBEPBE 2.687 7.631 7.642 7.644 7.619 7.619 7.619 7.616 7.616 7.630 7.616 7.616 7.633 7.649 7.614 7.614 7.650 7.614 7.614
PBEPBEultrafine 2.687 7.631 7.642 7.644 7.619 7.619 -23.667 7.616 7.616 7.630 7.616 7.616 7.633 7.649 7.614 7.614 7.650 7.614 7.614
PBE1PBE 2.520 7.553 7.568 7.571 7.550 7.550 7.549 7.543 7.543 7.558 7.543 7.543 7.558 7.576 7.542 7.542 7.577 7.542 7.542
HSEh1PBE 2.559 7.556 7.570 7.571 7.547 7.547 7.546 7.542 7.542 7.557 7.542 7.542 7.558 7.577 7.540 7.540 7.578 7.540 7.540
TPSSh         7.550   7.549     7.555         7.532        
wB97X-D     7.381   7.472   7.472   7.476       7.474 7.472 7.468     7.468  
B97D3   8.065     8.020   8.021   8.018                 8.023  
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
Moller Plesset perturbation MP2 1.662 7.091 7.204 7.108 7.204 7.204 7.205 7.204 7.204 7.236 7.238 7.238 7.017 7.205 7.248 7.267 7.211 7.251 7.270
MP2=FULL 1.681 7.099 7.226 7.112 7.226 7.226 7.227 7.236 7.236 7.280 7.335 7.335 7.043 7.219 7.300 7.342 7.226 7.305 7.345
MP3 1.920 7.317 7.397 7.338 7.400 7.400 7.399 7.394 7.394 7.410 7.402 7.402 7.170 7.399 7.410 7.410 7.402 7.410 7.410
MP3=FULL         7.418   7.418                        
MP4 2.031 7.416 7.467 7.439 7.471 7.471 7.470 7.464 7.464 7.475 7.466 7.466 7.226 7.470 7.473 7.475 7.472 7.473 7.475
MP4=FULL 2.036 7.419 7.486 7.440 7.488 7.488 7.488 7.487 7.487 7.509 7.539 7.539 7.241 7.481 7.519 7.538 7.484 7.519 7.538
Configuration interaction CID 2.090 7.468 7.510 7.491 7.513 7.513 7.512 7.507 7.507 7.520 7.512 7.512 7.242 7.514 7.519 7.522 7.514 7.519 7.522
CISD 2.090 7.472 7.516 7.495 7.519 7.519 7.519 7.512 7.512 7.527 7.518 7.518 7.258 7.519 7.525 7.529 7.520 7.526 7.529
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
Quadratic configuration interaction QCISD 2.090 7.472 7.516 7.495 7.519 7.519 7.519 7.512 7.512 7.527 7.518 7.518 7.258 7.519 7.529 7.529 7.520 7.526 7.529
QCISD(T) 2.090 7.472 7.516 7.495 7.519 7.519 7.519 7.512 7.512 7.527 7.518 7.518 7.258 7.519 7.525 7.529 7.520 7.526 7.529
Coupled Cluster CCD 2.090 7.468 7.510 7.491 7.513 7.513 7.512 7.507 7.507 7.520 7.512 7.512 7.242 7.514 7.519 7.522 7.514 7.519 7.522
CCSD   7.472 7.516 7.495 7.519 7.519 7.519 7.512 7.512 7.527 7.518 7.518 7.258 7.519 7.525 7.529 7.520 7.526 7.529
CCSD=FULL 2.079 7.471 7.527 7.493 7.529 7.529 7.528 7.514 7.514 7.548 7.554 7.554 7.262 7.525 7.552 7.566 7.526 7.553 7.567
CCSD(T)   7.472 7.516 7.495 7.519 7.519 7.519 7.512 7.512 7.527 7.518 7.518 7.258 7.519 7.526 7.528 7.522 7.526 7.528
CCSD(T)=FULL 2.088 7.473 7.532 7.495 7.533 7.533 7.342 7.531 7.531 7.556 7.580 7.580 7.270 7.527 7.562 7.582 7.530 7.564 7.582
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ

Ionization Energies in eV
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 6.770 6.769 6.632 6.626 6.808 5.353
density functional LSDA 8.005 8.005 7.871 7.872 8.044 8.175
SVWN 8.005 8.005 7.871 7.872 8.044 8.175
BLYP 7.503 7.503 7.365 7.361 7.544 7.653
B1B95 7.468 7.468 7.327 7.327 7.504 7.465
B3LYP 7.649 7.649 7.511 7.507 7.691 7.751
B3LYPultrafine 7.649 7.649 7.511 7.507 7.691 7.751
B3PW91 7.665 7.667 7.521 7.522 7.712 7.569
mPW1PW91 7.596 7.598 7.453 7.454 7.641 7.550
M06-2X 7.733 7.737 7.634 6.870 7.762 7.784
PBEPBE 7.548 7.551 7.407 7.408 7.593 7.644
PBEPBEultrafine 7.548 7.551 7.407 7.408 7.593 7.644
PBE1PBE 7.555 7.557 7.413 7.413 7.600 7.571
HSEh1PBE 7.546 7.548 7.404 7.404 7.591 7.571
Moller Plesset perturbation MP2 7.238 7.336 7.118 7.214 7.301 7.108
MP2=FULL 7.238 7.336 7.118 7.214 7.301 7.112
ROMP2 6.770   6.632   6.808 6.615
MP3 7.466 7.530 7.349 7.411 7.537 7.338
MP4 7.569 7.603 7.452 7.483 7.643 7.439
MP4=FULL 7.569 7.603 7.452 7.483 7.643 7.440
Configuration interaction CID 7.623 7.646 7.503 7.524 7.698 7.491
CISD 7.625 7.651 7.507 7.530 7.700 7.495
Quadratic configuration interaction QCISD 7.625 7.651 7.507 7.530 7.700 7.495
QCISD(T) 7.625 7.651 7.507 7.530 7.700 7.495
Coupled Cluster CCD 7.623 7.646 7.503 7.524 7.698 7.491
CCSD 7.625 7.651 7.507 7.530 7.700 7.495
CCSD=FULL 7.625 7.651 7.507 7.530 7.700 7.493
CCSD(T) 7.625 7.651 7.507 7.530 7.700 7.495
CCSD(T)=FULL 7.625 7.651 7.507 7.530 7.700 7.495
For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.