An operator solution (OS) delta(E, H) of the Schrodinger equation is obtain
ed from the Dirac delta-function mathematics. (i) In the coordinate represe
ntation, it is exactly the probability density in quantum mechanics (QM). (
ii) In the representation of the eigenfunction basis, this OS is exactly th
e local density of states (LDOS). (iii) In the ray space representation, th
is OS gives the quantum trajectory with a distinct classical trajectory in
its classical limit. These properties, including dynamics, are added to the
current probability interpretation of QM. When on surfaces, the QM traject
ory is helpful to localize the surface atom positions, say in scanning tunn
eling microscopy (STM). From this trajectory picture, we find one-to-one co
rrespondence between the number of trajectories and the number of eigen-equ
ations. Also we try to make a compatibility between the particle and wave f
unction. The dichotomy is discussed from the particle number viewpoints. Fo
r the H-atom, as a system of two particles, we find a theory in which this
system is 2-dimensional in classical treatments, but it is 3-dimensional in
QM. For experimental necessities in electronic devices and STM, we propose
our OS for resolving the negative differential conductance (NDC) phenomena
by extending this OS from standard positive to include negative values for
hole states by a consideration of the neutralization of electron-hole pair
in electric charges. This solves a longtime problem of incorporating the o
pposite charges into the original charge density in the density-functional
theory (DFT). This also differentiates the two mechanisms: the pure electro
n LDOS process and the recombination mechanism of electron-hole pairs which
emit photons like the displacement current or heat inside materials. Thus
the negative nature of these NDC can be considered as if final states of el
ectron transfer are hole states instead of electron states. The related phy
sics included are: electron and hole occupations in density of states (DOS)
; one particle representation and many-particle representation together wit
h an additional 'DOS representation'; atomic stability; properties of quant
um action function in 3-dimensional QM.