[HN Gopher] Commercial quantum computer identifies molecular can...
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Commercial quantum computer identifies molecular candidate for
better solar cell
Author : gmays
Score : 92 points
Date : 2023-08-03 18:58 UTC (4 hours ago)
(HTM) web link (www.ornl.gov)
(TXT) w3m dump (www.ornl.gov)
| mchannon wrote:
| H4 is impossible under any temperature or pressure. A hydrogen
| atom has one, count 'em, one electron to bond with. And bonds
| require, at minimum, two electrons shared between the two atoms.
| That's why H2 is pretty stable compared to monatomic H1. You'd
| have to rip up and throw out hundreds of years of chemistry for
| H4 to be possible.
|
| In other words, the computer spit out nonsense.
|
| This reminds me of the French guy in Holy Grail who giggles with
| his buddies "I told him we already got one.."
| [deleted]
| throwawaymaths wrote:
| This is wrong. For example, there are molecular ions H3+ and
| CH5+
|
| Some of the most common ions in the universe
| _ihaque wrote:
| H4 certainly sounds strange to me (and as other commenters have
| pointed out, this is a toy example, not a real molecule), but
| there are weird bond structures out there in real molecules
| that violate "at minimum, two electrons shared between the two
| atoms": https://en.wikipedia.org/wiki/Three-center_two-
| electron_bond.
|
| (The 3C-2E bonds in diborane are not linear, so that doesn't
| seem like what could be happening here.)
| selimthegrim wrote:
| Probably a couple points to note
|
| -this is intramolecular singlet fission within the H4 molecule.
|
| -The energy requirement (especially for intermolecular singlet
| fission) can be theoretically derived from the massive Thirring
| model assuming some degree of strong electron correlation.
| xwdv wrote:
| Imagine deploying a 12 inch by 12 inch solar panel someday and
| powering your entire home.
| throwaway5752 wrote:
| That is only 15 watts of total potential energy, regardless of
| pv panel efficiency, which will not power any homes.
| dgacmu wrote:
| Total solar insolation at peak is under about 400 watts per
| square meter. A one square foot panel at 100% efficiency is
| never [1] going to beat 40-50W even in the best circumstances,
| at the equator, and ignoring weather... and nighttime.
|
| [1] The sun becoming a red giant is hereby defined as an
| exception to this statement per the follow-up comments.
| xwdv wrote:
| You are forgetting the efficiency gains future homes will
| make so they require less power. Partly thanks to the rise of
| room temperature superconducting.
| colechristensen wrote:
| It's about 1 kW, not 400 W.
| SketchySeaBeast wrote:
| I get annoyed when commenters make back and forth claims
| without ever providing any citations so I did a Google and
| found myself on a NASA page. According to that page it's
| ~1360 W/m^2 at the top of the atmosphere, but by the time
| it gets to the surface it seems to average out to only
| about 340 W/m^2[1].
|
| [1] https://earthobservatory.nasa.gov/features/EnergyBalanc
| e/pag...
| fsh wrote:
| You misread the source. The average is _for the entire
| planet_ , parts of which are covered by clouds, and half
| of which is at night. 1 kW/m^2 is a typical value for
| peak insolations outside extreme latitudes. If the
| atmosphere absorbed significantly more than that, you
| could not see very far.
| SketchySeaBeast wrote:
| I didn't misread, I specified average. Maybe I needed to
| be more specific about what that meant, but I just wanted
| to get some real numbers involved instead of continual
| unsourced claims. I don't find he said / she said useful
| when we're talking about facts.
| perihelions wrote:
| - _" never"_
|
| technically
|
| - _"...heating due to gravitational contraction will also
| lead to hydrogen fusion in a shell just outside the core,
| where unfused hydrogen remains, contributing to the increased
| luminosity, which will eventually reach more than 1,000 times
| its present luminosity...[135] "_
|
| https://en.wikipedia.org/wiki/Sun#Life_phases
|
| 1.3 megawatts per square meter! An entire nuclear power plant
| on your roof, provided the weather allows, provided weather
| still exists. The future is _bright_.
| idiotsecant wrote:
| Futures so bright, I gotta wear 7.3 km thick ablative lead
| shielding!
| [deleted]
| peteradio wrote:
| About as useful as citing heat death when refuting climate
| change being caused by humans.
| ketralnis wrote:
| like every "well technically" you should read it is "not
| really"
| avmich wrote:
| Oh, you're on HN! How many technical advancements started
| with "technically" looking not too realistic at the
| moment?
| yellowcake0 wrote:
| > from months to a few weeks
|
| So a 4x speedup? A completely irrelevant performance improvement
| for a "quantum computer".
| fsh wrote:
| Both values refer to the quantum computer. A classical
| simulation would be many orders of magnitude faster.
| UberFly wrote:
| What will the world look like in 50 years with constant advances
| in quantum computing and AI.
| euroderf wrote:
| Hopefully we'll be on the road to the Culture, as described in
| the books of Ian M Banks. The missing piece will be FTL. Easy-
| peasy!
| peteradio wrote:
| Very very groovy for the survivors.
| nervousvarun wrote:
| This is why I like Gibson's future as outlined in his
| "Jackpot" trilogy...it's basically very very groovy for the
| survivors.
|
| https://en.wikipedia.org/wiki/The_Peripheral
| benreesman wrote:
| "You mean the whole world is funny Wilf?"
|
| "There is nothing funny about the Klept."
| yieldcrv wrote:
| Quantinuum H1-1 quantum computer
|
| https://www.quantinuum.com/hardware/h1
|
| huh, ok. discuss?
| powera wrote:
| As always, any press release about "quantum" is fake.
|
| What is "H-4"? How could this be used in solar panels? Did they
| use quantum computers for anything other than to spice up the
| press release?
|
| There are no answers.
| nulltxt wrote:
| H4 Seems to exist here
| https://en.m.wikipedia.org/wiki/Isotopes_of_hydrogen.
| powera wrote:
| Nope. That is discussing "an atom of hydrogen with 1 proton
| and 3 neutrons". Which kind-of exists, but is too unstable to
| be meaningful.
|
| The press release says it is a molecule of 4 hydrogen atoms.
| Neither the press release nor Wikipedia have any further
| thoughts as to how this is possible.
| comicjk wrote:
| I have long harbored an ambition of creating a Journal Of
| Implausible Chemistry, for the publication of research on
| hydrogen chains and other molecules cruelly disallowed by
| our impoverished reality.
| carterschonwald wrote:
| How can there be a 4 atom hydrogen molecule?
| persedes wrote:
| ~~Isotopes?~~ nvm just read the article:
|
| The linear H4 molecule is, simply, a molecule made of four
| hydrogen atoms arranged in a linear fashion.
| macksd wrote:
| I don't think so. Isotopes can influence mass and other
| nuclear characteristics, but it's really the electron
| configuration that determines the molecular possibilities.
| anyoneamous wrote:
| That's stretching the definition of "molecule" even worse
| than astrophysicists stretch the definition of "metal".
| kbenson wrote:
| I'm not really well versed in solar technology, but I found
| this[1] to maybe explain what this means. It looks like an ~5%
| overall theoretical efficiency gain might be expected, and if we
| can achieve the same over 90% of the theoretical maximum we get
| from silicon processes, that might be ~17% overall efficiency
| gains over our current silicon processes if some of the best case
| scenarios line up? (29.4% theoretical max to 34.6%).
|
| Someone that's more knowledgeable about this might completely
| invalidate my napkin math with actual insight or basic knowledge,
| so take their opinions over mine, since I'm just lightly scanning
| random internet info.
|
| 1: https://pubs.acs.org/doi/10.1021/acsenergylett.1c00972
| fsh wrote:
| The headline of the article is grossly misleading and has no
| relation to the paper it is based on. They modeled an extremely
| simplified toy molecule that doesn't occur in nature (a chain of
| four hydrogen atoms). Their quantum computer has 20 noisy qubits
| and can be trivially simulated and outperformed by a laptop. This
| is solid research, but any practical application is extremely far
| away, if at all possible.
| joshjob42 wrote:
| Moreover the actual circuits only use 5 qubits! You can
| simulate such systems in well under a millisecond on a modern
| laptop even with 100s of gates.
|
| They did a nice demonstration, but the hardware was irrelevant
| to the actual modeling of H4.
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(page generated 2023-08-03 23:00 UTC)