APSIDIUM  is a neologism from apsid es  and the Suffix ...ium. 

Not only is Apsis a proper acronym for the title mentioned above, but both the German word Apsis and the English apse and apsis come originally from the Greek word " ayiV " meaning " that which is fastened together, knot (in a net);  loop, arc, orbit (of a heavenly body)," etymologically " that which is fastened on or appended" - which fits nicely with our concept of an additional platform for providing further information about the structure of the elements.

What is APSIS (plural APSIDES )?

An Ap sis is the point in the orbit of a satellite where the body is neither approaching nor receding from another body about which it revolves.  Any elliptical orbit has two apsides.  At the p erig ee the moon or other satellite is as close as it ever gets to the earth, and it begins to move away;  at the ap og ee it is as far away as it gets, and it begins to move closer.  Similarly, in the orbit of the earth or another planet around the sun, the p erihelion is the point of closest approach and the ap helion is the point of furthest recession.  In the orbit of the stars in a binary star system, the p eriastron is the point of closest approach and the ap astron the point of furthest recession.  A line connecting the two apsidal points of an elliptical orbit (e.g., the aphelion and perihelion) is called the line of apsides;  it is the major axis of the ellipse.  This line may precess because of the gravitational influence of other bodies or relativistic effects.

The suffix -ium
[ For linquistic consistency, the names of all new elements shoud end in " -ium". ]
Pure Appl.chem.,Vol. 74,No. 5,pp. 787-791,2002 IUPAC
 

 
APSIDIUM --> A_ psi_dium --> A_ Y _dium

The prefix A- (Greek a - ) signifies negation (e.g.:  typical - a typical).
The Greek letter Psi (i.e., Y ) is also used as a symbol of Schrödinger's physical wave equations.  " aPsi" (or "non- Y ") thus indicates that the important concept here is not the wave equations but the particle.

The suffix -dium reinforces this stress on the material (non-wave) element.

The above definition negates the use of wave-functions in  formulas  only. The reference here is to the chemical, not the physical, circuit. It does not mean that transcription into wave functions in this form is impossible. For that reason please see article of Prof. Danail Bonchev; Texas A&M University Galveston: "Periodicity of the Chemical Elements and Nuclides: An Information Theoretic Analysis"   
  

APSIDIUM  

definition.pdf