Anti-bonding combinations of p(z)-orbtals on the O-atoms with sp-hybrids on the CH2 groups, and anti-bonding combinations of sp-hybrids on each CH2 group, each made up from the p(z) orbital on the C atom and s-orbitals on the H atoms. | 
Anti-bonding combinations of p-orbitals on the C and O atoms. |
| | HOMO | LUMO |
| C1 2px | -0.000000 | 0.421823 |
| C1 2py | 0.000000 | -0.421823 |
| C1 2pz | 0.204465 | -0.000000 |
| O2 2s | -0.000000 | -0.182302 |
| O2 2px | -0.000000 | 0.235475 |
| O2 2py | -0.000000 | -0.235475 |
| O2 2pz | -0.531833 | 0.000000 |
| O3 2s | -0.000000 | 0.182302 |
| O3 2px | 0.000000 | 0.235475 |
| O3 2py | -0.000000 | -0.235475 |
| O3 2pz | -0.531833 | 0.000000 |
| C4 2px | -0.000000 | 0.421823 |
| C4 2py | 0.000000 | -0.421823 |
| C4 2pz | 0.204465 | 0.000000 |
| H5 1s | 0.296098 | -0.000000 |
| H6 1s | 0.296098 | 0.000000 |
| H7 1s | -0.296098 | -0.000000 |
| H8 1s | -0.296098 | 0.000000 |
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