The dipole moment of the water molecule changes in response to variations in pressure and temperature. As indicated in an AIMD study by Kang et al., with increasing temperature, the dipole moment of water decreases due to the collapse of the hydrogen bond network. However, high pressure increases the average dipole moment. Besides, it was found that both high pressure and temperature induce the fluctuation of intramolecular charge, leading to a broader distribution of dipole moments.