Sun/Moon Midpoint: An Introduction
The Sun/Moon midpoint is a highly sensitive point on a chart, representing the integration of an individual's or composite's Sun and Moon energies, and is calculated by determining the precise midpoint between the Sun and the Moon. When you think of Sun energy, think of key words like: masculine, doing, ego expression, and yang. For Moon energy, think: emotional, intuition, being, feminine, and yin.
This midpoint is commonly described as representing a point of “inner marriage” and our most intimate relationships, be they platonic or romantic. In trying to understand the significance of this point, we can imagine that as an individual has integrated and disowned facets of their male and female energies, or archetypes, they will be attracted to people who embody them. Of course, the presence of Sun/Moon midpoint activations by aspecting planets in the Davison or individual charts is no guarantee that a relationship will work out. As always, that depends in large part on how well the individuals have integrated their own archetypal patterns.
When analyzing the Sun/Moon Midpoint in composite astrology, I like to determine the placement point in each of the native's charts, then calculate it on a Davison chart. By identifying where this point is found on each chart, one can begin looking for existing and potential activations across the charts being studied.
Because the Sun/Moon Midpoint is derived from an algebraic Arabian part and represents an activation point on the chart rather than a body producing an energetic frequency of its own, I use smaller orbs of two to three degrees and consider whether it is applying or separating.
I don't particularly enjoy calculating parts and midpoints manually, and therefore use a midpoint calculator such as the extensive one found at: http://www.astrologycircle.com/sun-moon-midpoint/. Happy research!