Cosmological query (qi, xing, zhi)?

Have recently been having another look at the Routledge Encyclopedia of Taoism. ( I know: a mis-spent youth!)

In the section on cosmology, it reads

The fivefold pattern first appears in the Han “weft texts” (weishu) and in the opening chapter of the Liezi. This pattern imagines a genesis in five stages called the Five Greats (wutai): taiyi (Great Simplicity), taichu (Great Beginning), taishi (Great Commencement), taisu (Great Plainness), and taiji (Great Ultimate). The second, third and fourth stages are the origin of pneuma, form and matter, respectively. They evolve progressively but are in a states of chaotic unity until they transform in the the One (the taiji) which is the “beginning of form”. This pattern was adopted by Taoist texts from the Tang period onward and was related to the wuxing [Vol I, p50].

Similarly, in the entry on “Wuji and Taiji” it states

For most Taoists…the taiji is the beginning of the world, but the wuji is unknowable. This view derives from the Han “weft texts” (weishu), where taiji is the last of the five precosmic geneses called the Five Greats (wutai), representing the instant when pneuma (qi), form (xing) and matter (zhi) are still merged together but are ready to part from each other [Vol II, p1058].

In Michael’s version of cosmology, the three-in-one contained in the “cosmic egg” is yuan jing, yuan qi and yuan shen. The encyclopedia is the first time I’ve come across the three-in-one being qi, xing, zhi. Anyone come across this before? Is it a case of different words for the same thing (i.e. jing, qi, shen = qi, xing, zhi)? Or different words because different things?