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Quantum computing is useless
(Fig.1) IBM error-prone useless quantum computer could only randomly sample fake trial wavefunctions chosen beforehand, which cannot predict anything nor discover drugs.
The recent overhyped media falsely insisted that IBM-Cleveland clinic-Riken quantum computer could simulate (= Not predict ) the largest 12635-atom protein, taking 100 hours (= impractical ), which may lead to useful drug discovery someday (= never happen ).
↑ The point is that they did Not say quantum mechanics or quantum computers could predict atomic energies, instead, they carefully chose the phrases such as "quantum computers could simulate molecules" and "model atomic behavior".
Because researchers know the old unrealistic quantum mechanics cannot solve its Schrödinger equation nor predict any atomic energies except for one-electron hydrogen atom, and today's error-prone parallel-world quantum computers cannot factor even the simple 21.
↑ This quantum simulation of the world's largest atoms will be easily accepted by some top journals, which is how IBM and academia manufacture the impractical mainstream science badly affecting the world's real science and education.
This-p.1-2nd-last-paragraph says -- Quantum mechanics impractical
"QM (= quantum mechanical ) methods apply the laws of QM to approximate the
wave function and to solve the Schrödinger equation. However, the Schrödinger equation cannot actually be solved for any but a
one-electron system (the hydrogen atom), and approximations need to be made ( This-p.4-left-last-paragraph )".
This-4th-last-paragraph says -- No quantum drug discovery
"For systems larger than a few particles, this becomes impossible really really quickly.... But even now, the strongest of computers, cannot analyze quantum systems larger than a few dozen atoms."
Despite the quantum mechanical inability to predict atomic energy, the media, academia and corporations falsely use the phrases such as "quantum mechanics or computers discovering drugs" to get research and investment money.
Even the overhyped Pfizer's researchers admit in this-p.13-right-last-paragraph saying
"Currently available quantum computers comprise a limited number of qubits, which prevents the application of our
method to real-world cases"
Actually the overhyped IBM news ( this-2nd-last-paragraph ) just vaguely says
"As quantum computers advance, integrating them into computational workflows could offer higher accuracy in energy calculations at larger scales, and potentially (= still useless ) open the door to simulating enzyme catalysts, drug mechanisms,"
↑ They carefully did Not say quantum mechanics could predict atomic behavior or drugs.
The unrealistic old quantum mechanical model not only cannot predict anything but also prevents useful experiments such as multi-probe atomic force microscopes clarifying atomic mechanisms, which is why quantum mechanics or computers or AI can never discover drugs.
Quantum mechanics cannot solve its Schrödinger equations nor predict any multi-electron atomic energies ( this-or this-12th-paragraph ).
So physicists have to choose fake trial antisymmetric wavefunctions (= basis sets ) or Slater determinants (= fake solutions ) out of infinite choices and infinite parameters ( this-4~5th-paragraphs ) to find ones giving the lowest energy in the impractical quantum approximate variational methods such as Hartree-Fock and configuration interaction (= CI ), which are too time-consuming, can not predict anything ( this-p.6-2.2~p.7, this-p.6-lower ).
These quantum mechanical approximate variational methods just choosing fake trial wavefunctions out of infinite choices allegedly give only upper bounds to exact atomic energies and cannot tell us how far above the exact atomic energies (= so cannot predict exact atomic energies, whether quantum computers or classical computers are used, this-9.80 ).
This or this-p.4-1st-paragraph says -- No quantum mechanical prediction
"So we do not have any way of
knowing how good or how bad our trial wave function is.
The variational method also does not tell us what kind of a trial function we must choose"
This IBM research used deceptive hybrid quantum-classical methods called Sample-based quantum diagonalization (= SQD, this-12~15th-paragraphs, this-8th-paragraph ) which is equal to quantum selected configuration interaction (= QSCI, this-p.25-p.27 ) that cannot predict atomic energies, as I said above.
↑ This IBM hybrid quantum SQD = QSCI method just artificially selects (fake) trial wavefunctions or Slater determinants ( step-4, this-p.2-left ), hence, its results depend on the artificial input values with No quantum mechanical prediction.
This-p.16-left-4~5th-paragraphs say -- No quantum computer prediction
"We remark that the performance of QSCI depends
highly on the quality of the input state."
"we proposed QSCI, a class of hybrid quantum-classical algorithms, to find low-lying eigenvalues and eigenstates of a many-electron Hamiltonian. Taking rough (= Not exact ) approximations of such eigenstates as input, QSCI selects (= Not predict ) important electron configurations to represent the eigenstates by sampling the input states on quantum computers, and then classically diagonalizes the Hamiltonian (= classical computer must calculate total energy )"
In this IBM research, for unsolvable Schrodinger equations, first they chose fake trial antisymmetric wavefunctions (= IBM used simple inaccurate minimal basis sets, this-p.6-right-2nd-paragraph = minimal basis set, this-p.14-Some notions = minimal basis set is a poor choice ).
And by using a classical computer, they roughly calculated energies of 12635 atoms by the impractical quantum approximate Hartree-Fock, MP2 (= wrong approximation ), CCSD after artificially ignoring some interactions due to time constraints ( this-7th-paragraph, this-p.3-Fig.1,p.4-left-lower,p.5-left ), which rough approximation just gave inaccurate atomic energies.
↑ Calculating all orbitals of 12635 atoms was too time-consuming and impossible, so IBM had to calculate only some chosen (= trimmed ) orbitals, determinants (= fragments, this-p.5-right~p.6-left ), which means this research gave up obtaining the exact energy of 12635 atoms from the beginning.
This or this-24~25th-paragraphs say -- Ignore some atomic energy
"By refining EWF to only consider those most important, local interactions (= illegitimately ignoring some atomic orbital energies, hence, unable to get exact atomic energy ), it became feasible to implement at the scale of Trypsin"
Their useless error-prone quantum computer was used only to randomly sample or pick orbitals for (unphysical) Slater determinants out of these artificially-chosen (fake) trial wavefunctions (= fragments, this-p.5-Fig.2 ) called ansatz whose energy was estimated by a classical computer (= using impractical quantum approximations such as Hartree-Fock, CCSD, MP2.. ) in advance ( this-p.2-A, this-p.2-last ).
This or this-last-6.Summary says -- Useless quantum computer
"In SQD, a quantum computer generate samples and a classical computer projects a Hamiltonian (= total energy ) onto a subspace spanned by the samples and diagonalizes it to compute eigenvalues and eigenvectors."
"The generated samples should be from the target (ground) state support." ← So quantum computers are meaningless, can only sample or pick trial wavefunctions from the already-prepared ground-state trial wavefunctions
This-p.3-2nd~3rd-paragraphs say -- Just choosing input wavefunctions
"The quality of the approximate energies and eigenstates obtained by QSCI (= SQD ) is determined by the choice of the input
state |Φ⟩ (= chosen trial wavefunction ). The input state must contain important bases to express the exact ground state with large weights so that
those bases appear frequently in the measurement results and are picked up in the selected CI calculation. One of the
ideal candidates for such an input state is the exact ground state" ← So just choosing the exact input trial wavefunction in advance with No quantum prediction.
↑ So quantum computer must (randomly) sample orbitals (= Slater determinants ) from trial wavefunctions artificially chosen to be close to ground-state (= this IBM research omitted some atomic interactions, so could Not get exact energy ) in advance without quantum prediction.
Then, the classical computer must recover the originally-chosen trial wavefunctions from the noisy quantum computer-sampled orbitals (= configuration recovery ) and calculate total energy (= Hamiltonian diagonalization, this-p.5-p.6, this or this-Background ).
↑ Diagnalization is calculating coefficient parameters giving the lowest energy in chosen trial wavefunctions ( this-7.10, this-p.5-2.4 ), which must be done by a classical computer (= today's error-prone quantum computers cannot calculate anything ).
This-4th-paragraph says -- Classical computer needed
"The technique underlying this result is Sample-based Quantum Diagonalization (SQD), the same method IBM has been developing as the flagship application for its QCSC architecture. In this workflow, a quantum processor (randomly) generates samples representing electronic configurations (Slater determinants). Classical supercomputers then take those samples through configuration recovery, subsampling, and subspace diagonalization to estimate ground-state energies."
↑ So IBM quantum computer just randomly sampling was useless and meaningless. Just the classical computer was needed to calculate (= Not predict ) atomic energy from artificially-chosen fake trial wavefunctions in this research, contrary to hypes ↓.
This review in the previous IBM SQD paper admits quantum computers are unneeded. ↓
p.2-last~p.3 says -- Quantum computer unneeded
"(i) a classical calculation ( of energy of chosen trial wavefunction by classical computers using quantum approximate CCSD or MP2 ) that (ii) informs
the choice of the parameters in the LUCJ wavefunction prepared on the quantum hardware. Then (iii) batches of bitstrings x (= electronic configurations) are measured (= sampled ) from such ( quantum ) hardware and (iv) such bitstrings are used to setup sub-spaces onto which (v) the Hamiltonian is projected and then classically
diagonalized (= a classical computer calculated atomic energy ).."
" The quantum part of the algorithm (iii) is therefore used to extract (= sample ) electronic configurations with a probability related to how much they were represented in the initial ( chosen ) wavefunction, that in turn was informed by the initial classical calculation. I think it should be made clear what is the practical advantage in extracting such configurations from the quantum hardware rather than directly from the initial classical wavefunction"
p.32-1st-paragraph says -- Quantum computer sampling meaningless
"In particular it is still Not clear if the SQD leads to a more
efficient sampling of the wavefunction w.r.t the classical approach" ← Quantum computer sampling is unneeded, meaningless.
This IBM research, which ignore some atomic orbitals and energies due to time constraints, could Not give exact atomic energies, hence they did Not compare their ( inaccurate ) calculated energies with experimental energies of 12635 atoms, hence, the phrase of "simulating atoms" is false. Drug discovery is definitely impossible.
Instead, this IBM research just compared their inaccurate hybrid quantum results with some classical computer results (= which were also wrong due to inaccurately chosen fake trial wavefunctions ), and showed No quantum computer advantage nor utility.
This-IBM-paper-p.10-right-2nd-paragraph says -- Wrong quantum results
"As a result, we cross the 12,000-atom barrier and perform
fragment calculations with accuracy higher than previously
conducted using HQC (= quantum-classical ) methods and matching leading classical
WF (= wavefunction ) method (= Not matching experimental results nor showing quantum advantage )" ← They just compared their inaccurate quantum results with some classical computer method, Not with experimental atomic energies.
This-8th-last~7th-last-paragraphs say -- No quantum computer advantage
"The work does Not yet outperform the best classical chemistry methods across all categories ( this-5th-last-paragraph )"
↑ This IBM research paper (= this-12th-paragraph or this-6th-paragraph-link ) ↓
p.1-right-last-paragraph says -- Quantum mechanical DFT fails
"The primary challenge towards this goal is to solve the
computationally costly quantum-mechanical many-electron
Schrodinger equation (SE) with accurate and scalable methods.
This task typically involves density functional theory (DFT)... DFT offers
more scalable solutions, but is based on semiempirical approximations that may Not produce accurate results
and lead to false positives and"
p.2-right-4th-paragraph says -- Quantum mechanics is impractical
"full configuration
interaction method (FCI = impractical quantum variational approximation just choosing fake wavefunctions or Slater determinants for unsolvable Schrodinger equation that cannot predict anything, this-p.3-3,p.7-5-Caveat ) are restricted to small and chemically
unrealistic contexts. Consequently, practical methods introduce
approximations ( this-p.2-introduction = giving up exact energy )"
p.3-left-1st-paragraph says -- Select wavefunction, No prediction
"The accuracy of SQD (= sampled based quantum diagonalization = quantum selected configuration interaction QSCI = deceptive hybrid quantum-classical method ) is
systematically improvable by increasing the number of selected configurations (= useless quantum computer can only randomly sample or choose fake trial wavefunctions or Slater determinants, which cannot predict exact atomic energy )"
p.3-right-last says -- Quantum SQD failed
"SQD
and ExtSQD may yield inaccurate results,"
p.4-left-1) says -- Classical Hartree-Fock calculation
"Given the geometry of a molecule we perform a Hartree Fock calculation (= inaccurate quantum approximation calculated by a classical computer ),.. to generate a set of molecular orbitals that are the input of quantum embedding"
p.5-Fig.2 shows --
Quantum computer unneeded
This useless IBM quantum computer was used only to sample trial wavefunctions (= unphysical Slater determinant parameters ). All atomic energy calculations such as configuration recovery (= generating usable trial wavefunctions from noisy quantum computer's sampling ) and diagonalization (= calculate
energy and coefficients, this-(61), this-p.5-(2.4) ) were conducted by a classical computer in this hybrid quantum method = SQD = QSCI ( this-p.4-1st-paragraph ).
p.5-left-1) says -- Ignore some atomic energy
"The standard construction of EWF (= embedded wavefunction ) fragments requires a full-system MP2 calculation (= too time-consuming, wrong non-variational quantum approximation giving false energies )... this is computationally
intractable,.. We lift this
limitation by
restricting,.. molecular orbitals
that are spatially localized within a sphere of center R and
radius Rcut = 7 A˚.. This choice is
empirical" ← So IBM empirically ignored some atomic interactions with
No quantum theoretical prediction
p.5-right-1) says -- Ignoring some atoms
"To achieve higher accuracy through improved
configuration selection, in this study we introduce TrimSQD.
This new variant incorporates the idea of trimming (= artificially ignoring some ) determinants"
p.6-right-2nd-paragraph says -- Choose inaccurate basis function
"For each complex, we obtain an initial geometry from
a PDB crystal structure (= using experimental data with No quantum prediction )..
We perform all quantum-mechanical calculations with the
STO-3G minimal basis set (= minimal basis set is the most inaccurate basis sets chosen for unsolvable Schrodinger equations that cannot predict anything, this-p.14-Some notions )"
p.8-left-A results say -- Inaccurate results
"EWF-TrimSQD (= this quantum hybrid method ) yield binding energies that
are comparable but too positive (= inaccurate )... the use of a minimal STO-3G basis set and the
values of η chosen to design fragments are likely causes for
this observation. Future work will (= still unrealized ) be directed at testing these
hypotheses and improving the accuracy of our results, for
example employing more realistic but comparably compact
bases (e.g. def2-svp split-valence polarized) combined with a
more flexible choice of η.." ← Results relying on artificial choice of basis sets and parameters means No quantum mechanical prediction
p.10-right-2nd-paragraph says -- Disagree with experiments
"using HQC methods and matching leading classical
WF methods (= No quantum computer advantage )" ← did Not say their "(inaccurate) hybrid-quantum results matching experimental atomic energy, because this research could Not get exact experimental atomic energy due to very rough approximation"
p.9-Table IX, p.10-Fig.6 -- Not compare with experiments
They compared
hybrid-quantum-SQD only with classical computer methods such as SCI, CCSD, DMRG (= more rough or inaccurate approximate version of the variational Full-CI or FCI method choosing free parameters with No quantum mechanical prediction, this-p.21 ) without comparing their (wrong) hybrid quantum results with experimental energy.
As a result, due to impractical quantum mechanics and its approximations that cannot predict anything, IBM hybrid quantum method called SQD could Not get nor predict exact atomic energy.
All researchers including IBM already know the impractical quantum mechanics can Not predict anything, and their error-prone quantum computers are hopeless forever (= so they are deceiving us ! ).
This is why they tend to use the misleading phrases such as " simulate (= Not predict ) atoms" and "discover drugs" in the overhyped fake news for investment and educational frauds which artificially- manufactured impractical mainstream science definitely has detrimental effect on real science curing diseases, education and people across the world.
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