  An unbiased spectral survey of V883 Ori, an eruptive young star, was carried
out with the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 6. The
detected line emission from various molecules reveals morphological/kinematical
features in both the Keplerian disk and the infalling envelope. A direct infall
signature, red-shifted absorption against continuum, has been detected in CO,
HCO$^+$, HCN, HNC, and H$_2$CO. HCO$^+$ and SO show large arm-like structures
that probably connect from an infalling envelope to the disk. HCN and H$_2$CO
reveal a distinct boundary between the inner and outer disk and reveal
tentative spiral structures connecting the outer disk to the inner disk. HNC
shows a large central emission hole (r $\sim$0.3\arcsec) due to its chemical
conversion to HCN at high temperatures. The HDO emission, a direct tracer of
the water sublimation region, has been detected in the disk. Molecular emission
from complex organic molecules (COMs) is confined within the HDO emission
boundary, and HCO$^+$ has an emission hole in its distribution due to its
destruction by water. Together, these features suggest that the current episode
of eruption in V883 Ori may be triggered by the infall from the envelope to the
outer disk, generating a spiral wave, which propagates inward and greatly
enhances the accretion onto the central star.
