## PH2PH-

 H3 \ H4 - P1 - P2 | H5
The ion charge is -1.

## Atomic Charges and Dipole Moment

P1 charge=-0.548
P2 charge=-0.775
H3 charge= 0.104
H4 charge= 0.107
H5 charge= 0.112
with a dipole moment of 2.53973 Debye

## Bond Lengths:

between P1 and P2: distance=2.239 ang___ between P1 and H3: distance=1.459 ang___
between P1 and H4: distance=1.458 ang___ between P2 and H5: distance=1.452 ang___

## Bond Angles:

for H3-P1-P2: angle=104.6 deg___ for H4-P1-P2: angle=104.0 deg___
for H5-P2-P1: angle=90.79 deg___

## Bond Orders (Mulliken):

between P1 and P2: order=0.755___ between P1 and H3: order=0.921___
between P1 and H4: order=0.925___ between P2 and H5: order=0.899___

## Best Lewis Structure

The Lewis structure that is closest to your structure is determined. The hybridization of the atoms in this idealized Lewis structure is given in the table below.

### Hybridization in the Best Lewis Structure

1. A bonding orbital for P1-P2 with 1.9902 electrons
__has 57.88% P 1 character in a s0.82 p3 hybrid
__has 42.12% P 2 character in a s0.43 p3 hybrid

2. A bonding orbital for P1-H3 with 1.9921 electrons
__has 46.37% P 1 character in a s0.52 p3 hybrid
__has 53.63% H 3 character in a s orbital

3. A bonding orbital for P1-H4 with 1.9921 electrons
__has 46.39% P 1 character in a s0.53 p3 hybrid
__has 53.61% H 4 character in a s orbital

4. A bonding orbital for P2-H5 with 1.9882 electrons
__has 45.85% P 2 character in a s0.52 p3 hybrid
__has 54.15% H 5 character in a s orbital

15. A lone pair orbital for P1 with 1.9945 electrons

16. A lone pair orbital for P2 with 1.9965 electrons

17. A lone pair orbital for P2 with 1.9195 electrons
__made from a p-pi orbital ( 99.92% p 0.07% d)

-With core pairs on: P 1 P 1 P 1 P 1 P 1 P 2 P 2 P 2 P 2 P 2 -

#### Donor Acceptor Interactions in the Best Lewis Structure

The localized orbitals in your best Lewis structure can interact strongly. A filled bonding or lone pair orbital can act as a donor and an empty or filled bonding, antibonding, or lone pair orbital can act as an acceptor. These interactions can strengthen and weaken bonds. For example, a lone pair donor->antibonding acceptor orbital interaction will weaken the bond associated with the antibonding orbital. Conversly, an interaction with a bonding pair as the acceptor will strengthen the bond. Strong electron delocalization in your best Lewis structure will also show up as donor-acceptor interactions.
Interactions greater than 20 kJ/mol for bonding and lone pair orbitals are listed below.

The interaction of the second lone pair donor orbital, 17, for P2 with the antibonding acceptor orbital, 78, for P1-H3 is 34.2 kJ/mol.

The interaction of the second lone pair donor orbital, 17, for P2 with the antibonding acceptor orbital, 79, for P1-H4 is 32.2 kJ/mol.

## Molecular Orbital Energies

The orbital energies are given in eV, where 1 eV=96.49 kJ/mol. Orbitals with very low energy are core 1s orbitals. More antibonding orbitals than you might expect are sometimes listed, because d orbitals are always included for heavy atoms and p orbitals are included for H atoms. Up spins are shown with a ^ and down spins are shown as v.

21 ----- 6.299
20 ----- 5.920

19 ----- 5.208

18 ----- 4.393

17 -^-v- 1.367

16 -^-v- -0.070

15 -^-v- -2.218

14 -^-v- -2.762

13 -^-v- -4.023

12 -^-v- -7.781

11 -^-v- -10.67

10 -^-v- -115.9

9 -^-v- -116.1
8 -^-v- -116.2

7 -^-v- -117.5

6 -^-v- -117.6
5 -^-v- -117.7

4 -^-v- -163.7

3 -^-v- -165.2

2 -^-v- -2061.

1 -^-v- -2062.

## Total Electronic Energy

The total electronic energy is a very large number, so by convention the units are given in atomic units, that is Hartrees (H). One Hartree is 2625.5 kJ/mol. The energy reference is for totally dissociated atoms. In other words, the reference state is a gas consisting of nuclei and electrons all at infinite distance from each other. The electronic energy includes all electric interactions and the kinetic energy of the electrons. This energy does not include translation, rotation, or vibration of the the molecule.

Total electronic energy = -684.5942084744 Hartrees